mirror of
https://github.com/ziglang/zig.git
synced 2024-11-26 15:12:31 +00:00
24babde746
I was just bitten by this footgun, where I actually wanted `sliceAsBytes` but unintentionally used `asBytes`, which in practice ignored all but the first element. Just add a comptime assertion to trigger a compile error in this case.
4727 lines
178 KiB
Zig
4727 lines
178 KiB
Zig
const std = @import("std.zig");
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const builtin = @import("builtin");
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const debug = std.debug;
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const assert = debug.assert;
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const math = std.math;
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const mem = @This();
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const testing = std.testing;
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const Endian = std.builtin.Endian;
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const native_endian = builtin.cpu.arch.endian();
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/// Compile time known minimum page size.
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/// https://github.com/ziglang/zig/issues/4082
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pub const page_size = switch (builtin.cpu.arch) {
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.wasm32, .wasm64 => 64 * 1024,
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.aarch64 => switch (builtin.os.tag) {
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.macos, .ios, .watchos, .tvos, .visionos => 16 * 1024,
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else => 4 * 1024,
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},
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.sparc64 => 8 * 1024,
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.loongarch32, .loongarch64 => switch (builtin.os.tag) {
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// Linux default KConfig value is 16KiB
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.linux => 16 * 1024,
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// FIXME:
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// There is no other OS supported yet. Use the same value
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// as Linux for now.
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else => 16 * 1024,
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},
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else => 4 * 1024,
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};
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/// The standard library currently thoroughly depends on byte size
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/// being 8 bits. (see the use of u8 throughout allocation code as
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/// the "byte" type.) Code which depends on this can reference this
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/// declaration. If we ever try to port the standard library to a
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/// non-8-bit-byte platform, this will allow us to search for things
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/// which need to be updated.
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pub const byte_size_in_bits = 8;
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pub const Allocator = @import("mem/Allocator.zig");
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/// Detects and asserts if the std.mem.Allocator interface is violated by the caller
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/// or the allocator.
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pub fn ValidationAllocator(comptime T: type) type {
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return struct {
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const Self = @This();
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underlying_allocator: T,
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pub fn init(underlying_allocator: T) @This() {
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return .{
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.underlying_allocator = underlying_allocator,
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};
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}
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pub fn allocator(self: *Self) Allocator {
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return .{
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.ptr = self,
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.vtable = &.{
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.alloc = alloc,
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.resize = resize,
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.free = free,
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},
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};
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}
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fn getUnderlyingAllocatorPtr(self: *Self) Allocator {
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if (T == Allocator) return self.underlying_allocator;
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return self.underlying_allocator.allocator();
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}
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pub fn alloc(
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ctx: *anyopaque,
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n: usize,
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log2_ptr_align: u8,
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ret_addr: usize,
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) ?[*]u8 {
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assert(n > 0);
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const self: *Self = @ptrCast(@alignCast(ctx));
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const underlying = self.getUnderlyingAllocatorPtr();
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const result = underlying.rawAlloc(n, log2_ptr_align, ret_addr) orelse
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return null;
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assert(mem.isAlignedLog2(@intFromPtr(result), log2_ptr_align));
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return result;
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}
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pub fn resize(
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ctx: *anyopaque,
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buf: []u8,
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log2_buf_align: u8,
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new_len: usize,
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ret_addr: usize,
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) bool {
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const self: *Self = @ptrCast(@alignCast(ctx));
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assert(buf.len > 0);
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const underlying = self.getUnderlyingAllocatorPtr();
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return underlying.rawResize(buf, log2_buf_align, new_len, ret_addr);
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}
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pub fn free(
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ctx: *anyopaque,
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buf: []u8,
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log2_buf_align: u8,
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ret_addr: usize,
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) void {
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const self: *Self = @ptrCast(@alignCast(ctx));
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assert(buf.len > 0);
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const underlying = self.getUnderlyingAllocatorPtr();
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underlying.rawFree(buf, log2_buf_align, ret_addr);
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}
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pub fn reset(self: *Self) void {
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self.underlying_allocator.reset();
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}
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};
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}
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pub fn validationWrap(allocator: anytype) ValidationAllocator(@TypeOf(allocator)) {
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return ValidationAllocator(@TypeOf(allocator)).init(allocator);
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}
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/// An allocator helper function. Adjusts an allocation length satisfy `len_align`.
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/// `full_len` should be the full capacity of the allocation which may be greater
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/// than the `len` that was requested. This function should only be used by allocators
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/// that are unaffected by `len_align`.
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pub fn alignAllocLen(full_len: usize, alloc_len: usize, len_align: u29) usize {
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assert(alloc_len > 0);
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assert(alloc_len >= len_align);
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assert(full_len >= alloc_len);
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if (len_align == 0)
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return alloc_len;
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const adjusted = alignBackwardAnyAlign(usize, full_len, len_align);
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assert(adjusted >= alloc_len);
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return adjusted;
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}
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const fail_allocator = Allocator{
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.ptr = undefined,
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.vtable = &failAllocator_vtable,
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};
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const failAllocator_vtable = Allocator.VTable{
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.alloc = failAllocatorAlloc,
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.resize = Allocator.noResize,
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.free = Allocator.noFree,
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};
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fn failAllocatorAlloc(_: *anyopaque, n: usize, log2_alignment: u8, ra: usize) ?[*]u8 {
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_ = n;
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_ = log2_alignment;
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_ = ra;
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return null;
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}
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test "Allocator basics" {
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try testing.expectError(error.OutOfMemory, fail_allocator.alloc(u8, 1));
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try testing.expectError(error.OutOfMemory, fail_allocator.allocSentinel(u8, 1, 0));
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}
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test "Allocator.resize" {
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const primitiveIntTypes = .{
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i8,
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u8,
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i16,
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u16,
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i32,
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u32,
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i64,
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u64,
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i128,
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u128,
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isize,
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usize,
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};
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inline for (primitiveIntTypes) |T| {
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var values = try testing.allocator.alloc(T, 100);
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defer testing.allocator.free(values);
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for (values, 0..) |*v, i| v.* = @as(T, @intCast(i));
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if (!testing.allocator.resize(values, values.len + 10)) return error.OutOfMemory;
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values = values.ptr[0 .. values.len + 10];
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try testing.expect(values.len == 110);
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}
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const primitiveFloatTypes = .{
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f16,
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f32,
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f64,
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f128,
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};
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inline for (primitiveFloatTypes) |T| {
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var values = try testing.allocator.alloc(T, 100);
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defer testing.allocator.free(values);
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for (values, 0..) |*v, i| v.* = @as(T, @floatFromInt(i));
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if (!testing.allocator.resize(values, values.len + 10)) return error.OutOfMemory;
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values = values.ptr[0 .. values.len + 10];
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try testing.expect(values.len == 110);
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}
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}
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/// Copy all of source into dest at position 0.
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/// dest.len must be >= source.len.
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/// If the slices overlap, dest.ptr must be <= src.ptr.
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pub fn copyForwards(comptime T: type, dest: []T, source: []const T) void {
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for (dest[0..source.len], source) |*d, s| d.* = s;
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}
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/// Copy all of source into dest at position 0.
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/// dest.len must be >= source.len.
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/// If the slices overlap, dest.ptr must be >= src.ptr.
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pub fn copyBackwards(comptime T: type, dest: []T, source: []const T) void {
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// TODO instead of manually doing this check for the whole array
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// and turning off runtime safety, the compiler should detect loops like
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// this and automatically omit safety checks for loops
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@setRuntimeSafety(false);
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assert(dest.len >= source.len);
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var i = source.len;
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while (i > 0) {
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i -= 1;
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dest[i] = source[i];
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}
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}
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/// Generally, Zig users are encouraged to explicitly initialize all fields of a struct explicitly rather than using this function.
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/// However, it is recognized that there are sometimes use cases for initializing all fields to a "zero" value. For example, when
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/// interfacing with a C API where this practice is more common and relied upon. If you are performing code review and see this
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/// function used, examine closely - it may be a code smell.
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/// Zero initializes the type.
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/// This can be used to zero-initialize any type for which it makes sense. Structs will be initialized recursively.
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pub fn zeroes(comptime T: type) T {
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switch (@typeInfo(T)) {
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.comptime_int, .int, .comptime_float, .float => {
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return @as(T, 0);
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},
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.@"enum" => {
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return @as(T, @enumFromInt(0));
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},
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.void => {
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return {};
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},
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.bool => {
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return false;
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},
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.optional, .null => {
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return null;
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},
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.@"struct" => |struct_info| {
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if (@sizeOf(T) == 0) return undefined;
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if (struct_info.layout == .@"extern") {
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var item: T = undefined;
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@memset(asBytes(&item), 0);
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return item;
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} else {
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var structure: T = undefined;
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inline for (struct_info.fields) |field| {
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if (!field.is_comptime) {
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@field(structure, field.name) = zeroes(field.type);
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}
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}
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return structure;
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}
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},
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.pointer => |ptr_info| {
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switch (ptr_info.size) {
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.Slice => {
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if (ptr_info.sentinel) |sentinel| {
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if (ptr_info.child == u8 and @as(*const u8, @ptrCast(sentinel)).* == 0) {
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return ""; // A special case for the most common use-case: null-terminated strings.
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}
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@compileError("Can't set a sentinel slice to zero. This would require allocating memory.");
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} else {
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return &[_]ptr_info.child{};
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}
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},
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.C => {
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return null;
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},
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.One, .Many => {
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if (ptr_info.is_allowzero) return @ptrFromInt(0);
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@compileError("Only nullable and allowzero pointers can be set to zero.");
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},
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}
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},
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.array => |info| {
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if (info.sentinel) |sentinel_ptr| {
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const sentinel = @as(*align(1) const info.child, @ptrCast(sentinel_ptr)).*;
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return [_:sentinel]info.child{zeroes(info.child)} ** info.len;
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}
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return [_]info.child{zeroes(info.child)} ** info.len;
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},
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.vector => |info| {
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return @splat(zeroes(info.child));
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},
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.@"union" => |info| {
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if (info.layout == .@"extern") {
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var item: T = undefined;
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@memset(asBytes(&item), 0);
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return item;
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}
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@compileError("Can't set a " ++ @typeName(T) ++ " to zero.");
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},
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.enum_literal,
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.error_union,
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.error_set,
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.@"fn",
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.type,
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.noreturn,
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.undefined,
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.@"opaque",
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.frame,
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.@"anyframe",
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=> {
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@compileError("Can't set a " ++ @typeName(T) ++ " to zero.");
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},
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}
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}
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test zeroes {
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const C_struct = extern struct {
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x: u32,
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y: u32 align(128),
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};
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var a = zeroes(C_struct);
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// Extern structs should have padding zeroed out.
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try testing.expectEqualSlices(u8, &[_]u8{0} ** @sizeOf(@TypeOf(a)), asBytes(&a));
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a.y += 10;
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try testing.expect(a.x == 0);
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try testing.expect(a.y == 10);
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const ZigStruct = struct {
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comptime comptime_field: u8 = 5,
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integral_types: struct {
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integer_0: i0,
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integer_8: i8,
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integer_16: i16,
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integer_32: i32,
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integer_64: i64,
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integer_128: i128,
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unsigned_0: u0,
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unsigned_8: u8,
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unsigned_16: u16,
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unsigned_32: u32,
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unsigned_64: u64,
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unsigned_128: u128,
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float_32: f32,
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float_64: f64,
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},
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pointers: struct {
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optional: ?*u8,
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c_pointer: [*c]u8,
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slice: []u8,
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nullTerminatedString: [:0]const u8,
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},
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array: [2]u32,
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vector_u32: @Vector(2, u32),
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vector_f32: @Vector(2, f32),
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vector_bool: @Vector(2, bool),
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optional_int: ?u8,
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empty: void,
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sentinel: [3:0]u8,
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};
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const b = zeroes(ZigStruct);
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try testing.expectEqual(@as(u8, 5), b.comptime_field);
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try testing.expectEqual(@as(i8, 0), b.integral_types.integer_0);
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try testing.expectEqual(@as(i8, 0), b.integral_types.integer_8);
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try testing.expectEqual(@as(i16, 0), b.integral_types.integer_16);
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try testing.expectEqual(@as(i32, 0), b.integral_types.integer_32);
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try testing.expectEqual(@as(i64, 0), b.integral_types.integer_64);
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try testing.expectEqual(@as(i128, 0), b.integral_types.integer_128);
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try testing.expectEqual(@as(u8, 0), b.integral_types.unsigned_0);
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try testing.expectEqual(@as(u8, 0), b.integral_types.unsigned_8);
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try testing.expectEqual(@as(u16, 0), b.integral_types.unsigned_16);
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try testing.expectEqual(@as(u32, 0), b.integral_types.unsigned_32);
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try testing.expectEqual(@as(u64, 0), b.integral_types.unsigned_64);
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try testing.expectEqual(@as(u128, 0), b.integral_types.unsigned_128);
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try testing.expectEqual(@as(f32, 0), b.integral_types.float_32);
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try testing.expectEqual(@as(f64, 0), b.integral_types.float_64);
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try testing.expectEqual(@as(?*u8, null), b.pointers.optional);
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try testing.expectEqual(@as([*c]u8, null), b.pointers.c_pointer);
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try testing.expectEqual(@as([]u8, &[_]u8{}), b.pointers.slice);
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try testing.expectEqual(@as([:0]const u8, ""), b.pointers.nullTerminatedString);
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for (b.array) |e| {
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try testing.expectEqual(@as(u32, 0), e);
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}
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try testing.expectEqual(@as(@TypeOf(b.vector_u32), @splat(0)), b.vector_u32);
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try testing.expectEqual(@as(@TypeOf(b.vector_f32), @splat(0.0)), b.vector_f32);
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try testing.expectEqual(@as(@TypeOf(b.vector_bool), @splat(false)), b.vector_bool);
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try testing.expectEqual(@as(?u8, null), b.optional_int);
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for (b.sentinel) |e| {
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try testing.expectEqual(@as(u8, 0), e);
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}
|
|
|
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const C_union = extern union {
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a: u8,
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b: u32,
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};
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|
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const c = zeroes(C_union);
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try testing.expectEqual(@as(u8, 0), c.a);
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try testing.expectEqual(@as(u32, 0), c.b);
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|
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const comptime_union = comptime zeroes(C_union);
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try testing.expectEqual(@as(u8, 0), comptime_union.a);
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try testing.expectEqual(@as(u32, 0), comptime_union.b);
|
|
|
|
// Ensure zero sized struct with fields is initialized correctly.
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_ = zeroes(struct { handle: void });
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|
}
|
|
|
|
/// Initializes all fields of the struct with their default value, or zero values if no default value is present.
|
|
/// If the field is present in the provided initial values, it will have that value instead.
|
|
/// Structs are initialized recursively.
|
|
pub fn zeroInit(comptime T: type, init: anytype) T {
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|
const Init = @TypeOf(init);
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|
|
|
switch (@typeInfo(T)) {
|
|
.@"struct" => |struct_info| {
|
|
switch (@typeInfo(Init)) {
|
|
.@"struct" => |init_info| {
|
|
if (init_info.is_tuple) {
|
|
if (init_info.fields.len > struct_info.fields.len) {
|
|
@compileError("Tuple initializer has more elements than there are fields in `" ++ @typeName(T) ++ "`");
|
|
}
|
|
} else {
|
|
inline for (init_info.fields) |field| {
|
|
if (!@hasField(T, field.name)) {
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|
@compileError("Encountered an initializer for `" ++ field.name ++ "`, but it is not a field of " ++ @typeName(T));
|
|
}
|
|
}
|
|
}
|
|
|
|
var value: T = if (struct_info.layout == .@"extern") zeroes(T) else undefined;
|
|
|
|
inline for (struct_info.fields, 0..) |field, i| {
|
|
if (field.is_comptime) {
|
|
continue;
|
|
}
|
|
|
|
if (init_info.is_tuple and init_info.fields.len > i) {
|
|
@field(value, field.name) = @field(init, init_info.fields[i].name);
|
|
} else if (@hasField(@TypeOf(init), field.name)) {
|
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switch (@typeInfo(field.type)) {
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|
.@"struct" => {
|
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@field(value, field.name) = zeroInit(field.type, @field(init, field.name));
|
|
},
|
|
else => {
|
|
@field(value, field.name) = @field(init, field.name);
|
|
},
|
|
}
|
|
} else if (field.default_value) |default_value_ptr| {
|
|
const default_value = @as(*align(1) const field.type, @ptrCast(default_value_ptr)).*;
|
|
@field(value, field.name) = default_value;
|
|
} else {
|
|
switch (@typeInfo(field.type)) {
|
|
.@"struct" => {
|
|
@field(value, field.name) = std.mem.zeroInit(field.type, .{});
|
|
},
|
|
else => {
|
|
@field(value, field.name) = std.mem.zeroes(@TypeOf(@field(value, field.name)));
|
|
},
|
|
}
|
|
}
|
|
}
|
|
|
|
return value;
|
|
},
|
|
else => {
|
|
@compileError("The initializer must be a struct");
|
|
},
|
|
}
|
|
},
|
|
else => {
|
|
@compileError("Can't default init a " ++ @typeName(T));
|
|
},
|
|
}
|
|
}
|
|
|
|
test zeroInit {
|
|
const I = struct {
|
|
d: f64,
|
|
};
|
|
|
|
const S = struct {
|
|
a: u32,
|
|
b: ?bool,
|
|
c: I,
|
|
e: [3]u8,
|
|
f: i64 = -1,
|
|
};
|
|
|
|
const s = zeroInit(S, .{
|
|
.a = 42,
|
|
});
|
|
|
|
try testing.expectEqual(S{
|
|
.a = 42,
|
|
.b = null,
|
|
.c = .{
|
|
.d = 0,
|
|
},
|
|
.e = [3]u8{ 0, 0, 0 },
|
|
.f = -1,
|
|
}, s);
|
|
|
|
const Color = struct {
|
|
r: u8,
|
|
g: u8,
|
|
b: u8,
|
|
a: u8,
|
|
};
|
|
|
|
const c = zeroInit(Color, .{ 255, 255 });
|
|
try testing.expectEqual(Color{
|
|
.r = 255,
|
|
.g = 255,
|
|
.b = 0,
|
|
.a = 0,
|
|
}, c);
|
|
|
|
const Foo = struct {
|
|
foo: u8 = 69,
|
|
bar: u8,
|
|
};
|
|
|
|
const f = zeroInit(Foo, .{});
|
|
try testing.expectEqual(Foo{
|
|
.foo = 69,
|
|
.bar = 0,
|
|
}, f);
|
|
|
|
const Bar = struct {
|
|
foo: u32 = 666,
|
|
bar: u32 = 420,
|
|
};
|
|
|
|
const b = zeroInit(Bar, .{69});
|
|
try testing.expectEqual(Bar{
|
|
.foo = 69,
|
|
.bar = 420,
|
|
}, b);
|
|
|
|
const Baz = struct {
|
|
foo: [:0]const u8 = "bar",
|
|
};
|
|
|
|
const baz1 = zeroInit(Baz, .{});
|
|
try testing.expectEqual(Baz{}, baz1);
|
|
|
|
const baz2 = zeroInit(Baz, .{ .foo = "zab" });
|
|
try testing.expectEqualSlices(u8, "zab", baz2.foo);
|
|
|
|
const NestedBaz = struct {
|
|
bbb: Baz,
|
|
};
|
|
const nested_baz = zeroInit(NestedBaz, .{});
|
|
try testing.expectEqual(NestedBaz{
|
|
.bbb = Baz{},
|
|
}, nested_baz);
|
|
}
|
|
|
|
pub fn sort(
|
|
comptime T: type,
|
|
items: []T,
|
|
context: anytype,
|
|
comptime lessThanFn: fn (@TypeOf(context), lhs: T, rhs: T) bool,
|
|
) void {
|
|
std.sort.block(T, items, context, lessThanFn);
|
|
}
|
|
|
|
pub fn sortUnstable(
|
|
comptime T: type,
|
|
items: []T,
|
|
context: anytype,
|
|
comptime lessThanFn: fn (@TypeOf(context), lhs: T, rhs: T) bool,
|
|
) void {
|
|
std.sort.pdq(T, items, context, lessThanFn);
|
|
}
|
|
|
|
/// TODO: currently this just calls `insertionSortContext`. The block sort implementation
|
|
/// in this file needs to be adapted to use the sort context.
|
|
pub fn sortContext(a: usize, b: usize, context: anytype) void {
|
|
std.sort.insertionContext(a, b, context);
|
|
}
|
|
|
|
pub fn sortUnstableContext(a: usize, b: usize, context: anytype) void {
|
|
std.sort.pdqContext(a, b, context);
|
|
}
|
|
|
|
/// Compares two slices of numbers lexicographically. O(n).
|
|
pub fn order(comptime T: type, lhs: []const T, rhs: []const T) math.Order {
|
|
const n = @min(lhs.len, rhs.len);
|
|
for (lhs[0..n], rhs[0..n]) |lhs_elem, rhs_elem| {
|
|
switch (math.order(lhs_elem, rhs_elem)) {
|
|
.eq => continue,
|
|
.lt => return .lt,
|
|
.gt => return .gt,
|
|
}
|
|
}
|
|
return math.order(lhs.len, rhs.len);
|
|
}
|
|
|
|
/// Compares two many-item pointers with NUL-termination lexicographically.
|
|
pub fn orderZ(comptime T: type, lhs: [*:0]const T, rhs: [*:0]const T) math.Order {
|
|
var i: usize = 0;
|
|
while (lhs[i] == rhs[i] and lhs[i] != 0) : (i += 1) {}
|
|
return math.order(lhs[i], rhs[i]);
|
|
}
|
|
|
|
test order {
|
|
try testing.expect(order(u8, "abcd", "bee") == .lt);
|
|
try testing.expect(order(u8, "abc", "abc") == .eq);
|
|
try testing.expect(order(u8, "abc", "abc0") == .lt);
|
|
try testing.expect(order(u8, "", "") == .eq);
|
|
try testing.expect(order(u8, "", "a") == .lt);
|
|
}
|
|
|
|
test orderZ {
|
|
try testing.expect(orderZ(u8, "abcd", "bee") == .lt);
|
|
try testing.expect(orderZ(u8, "abc", "abc") == .eq);
|
|
try testing.expect(orderZ(u8, "abc", "abc0") == .lt);
|
|
try testing.expect(orderZ(u8, "", "") == .eq);
|
|
try testing.expect(orderZ(u8, "", "a") == .lt);
|
|
}
|
|
|
|
/// Returns true if lhs < rhs, false otherwise
|
|
pub fn lessThan(comptime T: type, lhs: []const T, rhs: []const T) bool {
|
|
return order(T, lhs, rhs) == .lt;
|
|
}
|
|
|
|
test lessThan {
|
|
try testing.expect(lessThan(u8, "abcd", "bee"));
|
|
try testing.expect(!lessThan(u8, "abc", "abc"));
|
|
try testing.expect(lessThan(u8, "abc", "abc0"));
|
|
try testing.expect(!lessThan(u8, "", ""));
|
|
try testing.expect(lessThan(u8, "", "a"));
|
|
}
|
|
|
|
const eqlBytes_allowed = switch (builtin.zig_backend) {
|
|
// The SPIR-V backend does not support the optimized path yet.
|
|
.stage2_spirv64 => false,
|
|
// The RISC-V does not support vectors.
|
|
.stage2_riscv64 => false,
|
|
// The naive memory comparison implementation is more useful for fuzzers to
|
|
// find interesting inputs.
|
|
else => !builtin.fuzz,
|
|
};
|
|
|
|
/// Compares two slices and returns whether they are equal.
|
|
pub fn eql(comptime T: type, a: []const T, b: []const T) bool {
|
|
if (@sizeOf(T) == 0) return true;
|
|
if (!@inComptime() and std.meta.hasUniqueRepresentation(T) and eqlBytes_allowed) return eqlBytes(sliceAsBytes(a), sliceAsBytes(b));
|
|
|
|
if (a.len != b.len) return false;
|
|
if (a.len == 0 or a.ptr == b.ptr) return true;
|
|
|
|
for (a, b) |a_elem, b_elem| {
|
|
if (a_elem != b_elem) return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
/// std.mem.eql heavily optimized for slices of bytes.
|
|
fn eqlBytes(a: []const u8, b: []const u8) bool {
|
|
comptime assert(eqlBytes_allowed);
|
|
|
|
if (a.len != b.len) return false;
|
|
if (a.len == 0 or a.ptr == b.ptr) return true;
|
|
|
|
if (a.len <= 16) {
|
|
if (a.len < 4) {
|
|
const x = (a[0] ^ b[0]) | (a[a.len - 1] ^ b[a.len - 1]) | (a[a.len / 2] ^ b[a.len / 2]);
|
|
return x == 0;
|
|
}
|
|
var x: u32 = 0;
|
|
for ([_]usize{ 0, a.len - 4, (a.len / 8) * 4, a.len - 4 - ((a.len / 8) * 4) }) |n| {
|
|
x |= @as(u32, @bitCast(a[n..][0..4].*)) ^ @as(u32, @bitCast(b[n..][0..4].*));
|
|
}
|
|
return x == 0;
|
|
}
|
|
|
|
// Figure out the fastest way to scan through the input in chunks.
|
|
// Uses vectors when supported and falls back to usize/words when not.
|
|
const Scan = if (std.simd.suggestVectorLength(u8)) |vec_size|
|
|
struct {
|
|
pub const size = vec_size;
|
|
pub const Chunk = @Vector(size, u8);
|
|
pub inline fn isNotEqual(chunk_a: Chunk, chunk_b: Chunk) bool {
|
|
return @reduce(.Or, chunk_a != chunk_b);
|
|
}
|
|
}
|
|
else
|
|
struct {
|
|
pub const size = @sizeOf(usize);
|
|
pub const Chunk = usize;
|
|
pub inline fn isNotEqual(chunk_a: Chunk, chunk_b: Chunk) bool {
|
|
return chunk_a != chunk_b;
|
|
}
|
|
};
|
|
|
|
inline for (1..6) |s| {
|
|
const n = 16 << s;
|
|
if (n <= Scan.size and a.len <= n) {
|
|
const V = @Vector(n / 2, u8);
|
|
var x = @as(V, a[0 .. n / 2].*) ^ @as(V, b[0 .. n / 2].*);
|
|
x |= @as(V, a[a.len - n / 2 ..][0 .. n / 2].*) ^ @as(V, b[a.len - n / 2 ..][0 .. n / 2].*);
|
|
const zero: V = @splat(0);
|
|
return !@reduce(.Or, x != zero);
|
|
}
|
|
}
|
|
// Compare inputs in chunks at a time (excluding the last chunk).
|
|
for (0..(a.len - 1) / Scan.size) |i| {
|
|
const a_chunk: Scan.Chunk = @bitCast(a[i * Scan.size ..][0..Scan.size].*);
|
|
const b_chunk: Scan.Chunk = @bitCast(b[i * Scan.size ..][0..Scan.size].*);
|
|
if (Scan.isNotEqual(a_chunk, b_chunk)) return false;
|
|
}
|
|
|
|
// Compare the last chunk using an overlapping read (similar to the previous size strategies).
|
|
const last_a_chunk: Scan.Chunk = @bitCast(a[a.len - Scan.size ..][0..Scan.size].*);
|
|
const last_b_chunk: Scan.Chunk = @bitCast(b[a.len - Scan.size ..][0..Scan.size].*);
|
|
return !Scan.isNotEqual(last_a_chunk, last_b_chunk);
|
|
}
|
|
|
|
/// Compares two slices and returns the index of the first inequality.
|
|
/// Returns null if the slices are equal.
|
|
pub fn indexOfDiff(comptime T: type, a: []const T, b: []const T) ?usize {
|
|
const shortest = @min(a.len, b.len);
|
|
if (a.ptr == b.ptr)
|
|
return if (a.len == b.len) null else shortest;
|
|
var index: usize = 0;
|
|
while (index < shortest) : (index += 1) if (a[index] != b[index]) return index;
|
|
return if (a.len == b.len) null else shortest;
|
|
}
|
|
|
|
test indexOfDiff {
|
|
try testing.expectEqual(indexOfDiff(u8, "one", "one"), null);
|
|
try testing.expectEqual(indexOfDiff(u8, "one two", "one"), 3);
|
|
try testing.expectEqual(indexOfDiff(u8, "one", "one two"), 3);
|
|
try testing.expectEqual(indexOfDiff(u8, "one twx", "one two"), 6);
|
|
try testing.expectEqual(indexOfDiff(u8, "xne", "one"), 0);
|
|
}
|
|
|
|
/// Takes a sentinel-terminated pointer and returns a slice preserving pointer attributes.
|
|
/// `[*c]` pointers are assumed to be 0-terminated and assumed to not be allowzero.
|
|
fn Span(comptime T: type) type {
|
|
switch (@typeInfo(T)) {
|
|
.optional => |optional_info| {
|
|
return ?Span(optional_info.child);
|
|
},
|
|
.pointer => |ptr_info| {
|
|
var new_ptr_info = ptr_info;
|
|
switch (ptr_info.size) {
|
|
.C => {
|
|
new_ptr_info.sentinel = &@as(ptr_info.child, 0);
|
|
new_ptr_info.is_allowzero = false;
|
|
},
|
|
.Many => if (ptr_info.sentinel == null) @compileError("invalid type given to std.mem.span: " ++ @typeName(T)),
|
|
.One, .Slice => @compileError("invalid type given to std.mem.span: " ++ @typeName(T)),
|
|
}
|
|
new_ptr_info.size = .Slice;
|
|
return @Type(.{ .pointer = new_ptr_info });
|
|
},
|
|
else => {},
|
|
}
|
|
@compileError("invalid type given to std.mem.span: " ++ @typeName(T));
|
|
}
|
|
|
|
test Span {
|
|
try testing.expect(Span([*:1]u16) == [:1]u16);
|
|
try testing.expect(Span(?[*:1]u16) == ?[:1]u16);
|
|
try testing.expect(Span([*:1]const u8) == [:1]const u8);
|
|
try testing.expect(Span(?[*:1]const u8) == ?[:1]const u8);
|
|
try testing.expect(Span([*c]u16) == [:0]u16);
|
|
try testing.expect(Span(?[*c]u16) == ?[:0]u16);
|
|
try testing.expect(Span([*c]const u8) == [:0]const u8);
|
|
try testing.expect(Span(?[*c]const u8) == ?[:0]const u8);
|
|
}
|
|
|
|
/// Takes a sentinel-terminated pointer and returns a slice, iterating over the
|
|
/// memory to find the sentinel and determine the length.
|
|
/// Pointer attributes such as const are preserved.
|
|
/// `[*c]` pointers are assumed to be non-null and 0-terminated.
|
|
pub fn span(ptr: anytype) Span(@TypeOf(ptr)) {
|
|
if (@typeInfo(@TypeOf(ptr)) == .optional) {
|
|
if (ptr) |non_null| {
|
|
return span(non_null);
|
|
} else {
|
|
return null;
|
|
}
|
|
}
|
|
const Result = Span(@TypeOf(ptr));
|
|
const l = len(ptr);
|
|
const ptr_info = @typeInfo(Result).pointer;
|
|
if (ptr_info.sentinel) |s_ptr| {
|
|
const s = @as(*align(1) const ptr_info.child, @ptrCast(s_ptr)).*;
|
|
return ptr[0..l :s];
|
|
} else {
|
|
return ptr[0..l];
|
|
}
|
|
}
|
|
|
|
test span {
|
|
var array: [5]u16 = [_]u16{ 1, 2, 3, 4, 5 };
|
|
const ptr = @as([*:3]u16, array[0..2 :3]);
|
|
try testing.expect(eql(u16, span(ptr), &[_]u16{ 1, 2 }));
|
|
try testing.expectEqual(@as(?[:0]u16, null), span(@as(?[*:0]u16, null)));
|
|
}
|
|
|
|
/// Helper for the return type of sliceTo()
|
|
fn SliceTo(comptime T: type, comptime end: std.meta.Elem(T)) type {
|
|
switch (@typeInfo(T)) {
|
|
.optional => |optional_info| {
|
|
return ?SliceTo(optional_info.child, end);
|
|
},
|
|
.pointer => |ptr_info| {
|
|
var new_ptr_info = ptr_info;
|
|
new_ptr_info.size = .Slice;
|
|
switch (ptr_info.size) {
|
|
.One => switch (@typeInfo(ptr_info.child)) {
|
|
.array => |array_info| {
|
|
new_ptr_info.child = array_info.child;
|
|
// The return type must only be sentinel terminated if we are guaranteed
|
|
// to find the value searched for, which is only the case if it matches
|
|
// the sentinel of the type passed.
|
|
if (array_info.sentinel) |sentinel_ptr| {
|
|
const sentinel = @as(*align(1) const array_info.child, @ptrCast(sentinel_ptr)).*;
|
|
if (end == sentinel) {
|
|
new_ptr_info.sentinel = &end;
|
|
} else {
|
|
new_ptr_info.sentinel = null;
|
|
}
|
|
}
|
|
},
|
|
else => {},
|
|
},
|
|
.Many, .Slice => {
|
|
// The return type must only be sentinel terminated if we are guaranteed
|
|
// to find the value searched for, which is only the case if it matches
|
|
// the sentinel of the type passed.
|
|
if (ptr_info.sentinel) |sentinel_ptr| {
|
|
const sentinel = @as(*align(1) const ptr_info.child, @ptrCast(sentinel_ptr)).*;
|
|
if (end == sentinel) {
|
|
new_ptr_info.sentinel = &end;
|
|
} else {
|
|
new_ptr_info.sentinel = null;
|
|
}
|
|
}
|
|
},
|
|
.C => {
|
|
new_ptr_info.sentinel = &end;
|
|
// C pointers are always allowzero, but we don't want the return type to be.
|
|
assert(new_ptr_info.is_allowzero);
|
|
new_ptr_info.is_allowzero = false;
|
|
},
|
|
}
|
|
return @Type(.{ .pointer = new_ptr_info });
|
|
},
|
|
else => {},
|
|
}
|
|
@compileError("invalid type given to std.mem.sliceTo: " ++ @typeName(T));
|
|
}
|
|
|
|
/// Takes an array, a pointer to an array, a sentinel-terminated pointer, or a slice and
|
|
/// iterates searching for the first occurrence of `end`, returning the scanned slice.
|
|
/// If `end` is not found, the full length of the array/slice/sentinel terminated pointer is returned.
|
|
/// If the pointer type is sentinel terminated and `end` matches that terminator, the
|
|
/// resulting slice is also sentinel terminated.
|
|
/// Pointer properties such as mutability and alignment are preserved.
|
|
/// C pointers are assumed to be non-null.
|
|
pub fn sliceTo(ptr: anytype, comptime end: std.meta.Elem(@TypeOf(ptr))) SliceTo(@TypeOf(ptr), end) {
|
|
if (@typeInfo(@TypeOf(ptr)) == .optional) {
|
|
const non_null = ptr orelse return null;
|
|
return sliceTo(non_null, end);
|
|
}
|
|
const Result = SliceTo(@TypeOf(ptr), end);
|
|
const length = lenSliceTo(ptr, end);
|
|
const ptr_info = @typeInfo(Result).pointer;
|
|
if (ptr_info.sentinel) |s_ptr| {
|
|
const s = @as(*align(1) const ptr_info.child, @ptrCast(s_ptr)).*;
|
|
return ptr[0..length :s];
|
|
} else {
|
|
return ptr[0..length];
|
|
}
|
|
}
|
|
|
|
test sliceTo {
|
|
try testing.expectEqualSlices(u8, "aoeu", sliceTo("aoeu", 0));
|
|
|
|
{
|
|
var array: [5]u16 = [_]u16{ 1, 2, 3, 4, 5 };
|
|
try testing.expectEqualSlices(u16, &array, sliceTo(&array, 0));
|
|
try testing.expectEqualSlices(u16, array[0..3], sliceTo(array[0..3], 0));
|
|
try testing.expectEqualSlices(u16, array[0..2], sliceTo(&array, 3));
|
|
try testing.expectEqualSlices(u16, array[0..2], sliceTo(array[0..3], 3));
|
|
|
|
const sentinel_ptr = @as([*:5]u16, @ptrCast(&array));
|
|
try testing.expectEqualSlices(u16, array[0..2], sliceTo(sentinel_ptr, 3));
|
|
try testing.expectEqualSlices(u16, array[0..4], sliceTo(sentinel_ptr, 99));
|
|
|
|
const optional_sentinel_ptr = @as(?[*:5]u16, @ptrCast(&array));
|
|
try testing.expectEqualSlices(u16, array[0..2], sliceTo(optional_sentinel_ptr, 3).?);
|
|
try testing.expectEqualSlices(u16, array[0..4], sliceTo(optional_sentinel_ptr, 99).?);
|
|
|
|
const c_ptr = @as([*c]u16, &array);
|
|
try testing.expectEqualSlices(u16, array[0..2], sliceTo(c_ptr, 3));
|
|
|
|
const slice: []u16 = &array;
|
|
try testing.expectEqualSlices(u16, array[0..2], sliceTo(slice, 3));
|
|
try testing.expectEqualSlices(u16, &array, sliceTo(slice, 99));
|
|
|
|
const sentinel_slice: [:5]u16 = array[0..4 :5];
|
|
try testing.expectEqualSlices(u16, array[0..2], sliceTo(sentinel_slice, 3));
|
|
try testing.expectEqualSlices(u16, array[0..4], sliceTo(sentinel_slice, 99));
|
|
}
|
|
{
|
|
var sentinel_array: [5:0]u16 = [_:0]u16{ 1, 2, 3, 4, 5 };
|
|
try testing.expectEqualSlices(u16, sentinel_array[0..2], sliceTo(&sentinel_array, 3));
|
|
try testing.expectEqualSlices(u16, &sentinel_array, sliceTo(&sentinel_array, 0));
|
|
try testing.expectEqualSlices(u16, &sentinel_array, sliceTo(&sentinel_array, 99));
|
|
}
|
|
|
|
try testing.expectEqual(@as(?[]u8, null), sliceTo(@as(?[]u8, null), 0));
|
|
}
|
|
|
|
/// Private helper for sliceTo(). If you want the length, use sliceTo(foo, x).len
|
|
fn lenSliceTo(ptr: anytype, comptime end: std.meta.Elem(@TypeOf(ptr))) usize {
|
|
switch (@typeInfo(@TypeOf(ptr))) {
|
|
.pointer => |ptr_info| switch (ptr_info.size) {
|
|
.One => switch (@typeInfo(ptr_info.child)) {
|
|
.array => |array_info| {
|
|
if (array_info.sentinel) |sentinel_ptr| {
|
|
const sentinel = @as(*align(1) const array_info.child, @ptrCast(sentinel_ptr)).*;
|
|
if (sentinel == end) {
|
|
return indexOfSentinel(array_info.child, end, ptr);
|
|
}
|
|
}
|
|
return indexOfScalar(array_info.child, ptr, end) orelse array_info.len;
|
|
},
|
|
else => {},
|
|
},
|
|
.Many => if (ptr_info.sentinel) |sentinel_ptr| {
|
|
const sentinel = @as(*align(1) const ptr_info.child, @ptrCast(sentinel_ptr)).*;
|
|
if (sentinel == end) {
|
|
return indexOfSentinel(ptr_info.child, end, ptr);
|
|
}
|
|
// We're looking for something other than the sentinel,
|
|
// but iterating past the sentinel would be a bug so we need
|
|
// to check for both.
|
|
var i: usize = 0;
|
|
while (ptr[i] != end and ptr[i] != sentinel) i += 1;
|
|
return i;
|
|
},
|
|
.C => {
|
|
assert(ptr != null);
|
|
return indexOfSentinel(ptr_info.child, end, ptr);
|
|
},
|
|
.Slice => {
|
|
if (ptr_info.sentinel) |sentinel_ptr| {
|
|
const sentinel = @as(*align(1) const ptr_info.child, @ptrCast(sentinel_ptr)).*;
|
|
if (sentinel == end) {
|
|
return indexOfSentinel(ptr_info.child, sentinel, ptr);
|
|
}
|
|
}
|
|
return indexOfScalar(ptr_info.child, ptr, end) orelse ptr.len;
|
|
},
|
|
},
|
|
else => {},
|
|
}
|
|
@compileError("invalid type given to std.mem.sliceTo: " ++ @typeName(@TypeOf(ptr)));
|
|
}
|
|
|
|
test lenSliceTo {
|
|
try testing.expect(lenSliceTo("aoeu", 0) == 4);
|
|
|
|
{
|
|
var array: [5]u16 = [_]u16{ 1, 2, 3, 4, 5 };
|
|
try testing.expectEqual(@as(usize, 5), lenSliceTo(&array, 0));
|
|
try testing.expectEqual(@as(usize, 3), lenSliceTo(array[0..3], 0));
|
|
try testing.expectEqual(@as(usize, 2), lenSliceTo(&array, 3));
|
|
try testing.expectEqual(@as(usize, 2), lenSliceTo(array[0..3], 3));
|
|
|
|
const sentinel_ptr = @as([*:5]u16, @ptrCast(&array));
|
|
try testing.expectEqual(@as(usize, 2), lenSliceTo(sentinel_ptr, 3));
|
|
try testing.expectEqual(@as(usize, 4), lenSliceTo(sentinel_ptr, 99));
|
|
|
|
const c_ptr = @as([*c]u16, &array);
|
|
try testing.expectEqual(@as(usize, 2), lenSliceTo(c_ptr, 3));
|
|
|
|
const slice: []u16 = &array;
|
|
try testing.expectEqual(@as(usize, 2), lenSliceTo(slice, 3));
|
|
try testing.expectEqual(@as(usize, 5), lenSliceTo(slice, 99));
|
|
|
|
const sentinel_slice: [:5]u16 = array[0..4 :5];
|
|
try testing.expectEqual(@as(usize, 2), lenSliceTo(sentinel_slice, 3));
|
|
try testing.expectEqual(@as(usize, 4), lenSliceTo(sentinel_slice, 99));
|
|
}
|
|
{
|
|
var sentinel_array: [5:0]u16 = [_:0]u16{ 1, 2, 3, 4, 5 };
|
|
try testing.expectEqual(@as(usize, 2), lenSliceTo(&sentinel_array, 3));
|
|
try testing.expectEqual(@as(usize, 5), lenSliceTo(&sentinel_array, 0));
|
|
try testing.expectEqual(@as(usize, 5), lenSliceTo(&sentinel_array, 99));
|
|
}
|
|
}
|
|
|
|
/// Takes a sentinel-terminated pointer and iterates over the memory to find the
|
|
/// sentinel and determine the length.
|
|
/// `[*c]` pointers are assumed to be non-null and 0-terminated.
|
|
pub fn len(value: anytype) usize {
|
|
switch (@typeInfo(@TypeOf(value))) {
|
|
.pointer => |info| switch (info.size) {
|
|
.Many => {
|
|
const sentinel_ptr = info.sentinel orelse
|
|
@compileError("invalid type given to std.mem.len: " ++ @typeName(@TypeOf(value)));
|
|
const sentinel = @as(*align(1) const info.child, @ptrCast(sentinel_ptr)).*;
|
|
return indexOfSentinel(info.child, sentinel, value);
|
|
},
|
|
.C => {
|
|
assert(value != null);
|
|
return indexOfSentinel(info.child, 0, value);
|
|
},
|
|
else => @compileError("invalid type given to std.mem.len: " ++ @typeName(@TypeOf(value))),
|
|
},
|
|
else => @compileError("invalid type given to std.mem.len: " ++ @typeName(@TypeOf(value))),
|
|
}
|
|
}
|
|
|
|
test len {
|
|
var array: [5]u16 = [_]u16{ 1, 2, 0, 4, 5 };
|
|
const ptr = @as([*:4]u16, array[0..3 :4]);
|
|
try testing.expect(len(ptr) == 3);
|
|
const c_ptr = @as([*c]u16, ptr);
|
|
try testing.expect(len(c_ptr) == 2);
|
|
}
|
|
|
|
const backend_supports_vectors = switch (builtin.zig_backend) {
|
|
.stage2_llvm, .stage2_c => true,
|
|
else => false,
|
|
};
|
|
|
|
pub fn indexOfSentinel(comptime T: type, comptime sentinel: T, p: [*:sentinel]const T) usize {
|
|
var i: usize = 0;
|
|
|
|
if (backend_supports_vectors and
|
|
!std.debug.inValgrind() and // https://github.com/ziglang/zig/issues/17717
|
|
!@inComptime() and
|
|
(@typeInfo(T) == .int or @typeInfo(T) == .float) and std.math.isPowerOfTwo(@bitSizeOf(T)))
|
|
{
|
|
switch (@import("builtin").cpu.arch) {
|
|
// The below branch assumes that reading past the end of the buffer is valid, as long
|
|
// as we don't read into a new page. This should be the case for most architectures
|
|
// which use paged memory, however should be confirmed before adding a new arch below.
|
|
.aarch64, .x86, .x86_64 => if (std.simd.suggestVectorLength(T)) |block_len| {
|
|
const block_size = @sizeOf(T) * block_len;
|
|
const Block = @Vector(block_len, T);
|
|
const mask: Block = @splat(sentinel);
|
|
|
|
comptime std.debug.assert(std.mem.page_size % block_size == 0);
|
|
|
|
// First block may be unaligned
|
|
const start_addr = @intFromPtr(&p[i]);
|
|
const offset_in_page = start_addr & (std.mem.page_size - 1);
|
|
if (offset_in_page <= std.mem.page_size - block_size) {
|
|
// Will not read past the end of a page, full block.
|
|
const block: Block = p[i..][0..block_len].*;
|
|
const matches = block == mask;
|
|
if (@reduce(.Or, matches)) {
|
|
return i + std.simd.firstTrue(matches).?;
|
|
}
|
|
|
|
i += @divExact(std.mem.alignForward(usize, start_addr, block_size) - start_addr, @sizeOf(T));
|
|
} else {
|
|
// Would read over a page boundary. Per-byte at a time until aligned or found.
|
|
// 0.39% chance this branch is taken for 4K pages at 16b block length.
|
|
//
|
|
// An alternate strategy is to do read a full block (the last in the page) and
|
|
// mask the entries before the pointer.
|
|
while ((@intFromPtr(&p[i]) & (block_size - 1)) != 0) : (i += 1) {
|
|
if (p[i] == sentinel) return i;
|
|
}
|
|
}
|
|
|
|
std.debug.assert(std.mem.isAligned(@intFromPtr(&p[i]), block_size));
|
|
while (true) {
|
|
const block: *const Block = @ptrCast(@alignCast(p[i..][0..block_len]));
|
|
const matches = block.* == mask;
|
|
if (@reduce(.Or, matches)) {
|
|
return i + std.simd.firstTrue(matches).?;
|
|
}
|
|
i += block_len;
|
|
}
|
|
},
|
|
else => {},
|
|
}
|
|
}
|
|
|
|
while (p[i] != sentinel) {
|
|
i += 1;
|
|
}
|
|
return i;
|
|
}
|
|
|
|
test "indexOfSentinel vector paths" {
|
|
const Types = [_]type{ u8, u16, u32, u64 };
|
|
const allocator = std.testing.allocator;
|
|
|
|
inline for (Types) |T| {
|
|
const block_len = std.simd.suggestVectorLength(T) orelse continue;
|
|
|
|
// Allocate three pages so we guarantee a page-crossing address with a full page after
|
|
const memory = try allocator.alloc(T, 3 * std.mem.page_size / @sizeOf(T));
|
|
defer allocator.free(memory);
|
|
@memset(memory, 0xaa);
|
|
|
|
// Find starting page-alignment = 0
|
|
var start: usize = 0;
|
|
const start_addr = @intFromPtr(&memory);
|
|
start += (std.mem.alignForward(usize, start_addr, std.mem.page_size) - start_addr) / @sizeOf(T);
|
|
try testing.expect(start < std.mem.page_size / @sizeOf(T));
|
|
|
|
// Validate all sub-block alignments
|
|
const search_len = std.mem.page_size / @sizeOf(T);
|
|
memory[start + search_len] = 0;
|
|
for (0..block_len) |offset| {
|
|
try testing.expectEqual(search_len - offset, indexOfSentinel(T, 0, @ptrCast(&memory[start + offset])));
|
|
}
|
|
memory[start + search_len] = 0xaa;
|
|
|
|
// Validate page boundary crossing
|
|
const start_page_boundary = start + (std.mem.page_size / @sizeOf(T));
|
|
memory[start_page_boundary + block_len] = 0;
|
|
for (0..block_len) |offset| {
|
|
try testing.expectEqual(2 * block_len - offset, indexOfSentinel(T, 0, @ptrCast(&memory[start_page_boundary - block_len + offset])));
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Returns true if all elements in a slice are equal to the scalar value provided
|
|
pub fn allEqual(comptime T: type, slice: []const T, scalar: T) bool {
|
|
for (slice) |item| {
|
|
if (item != scalar) return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
/// Remove a set of values from the beginning of a slice.
|
|
pub fn trimLeft(comptime T: type, slice: []const T, values_to_strip: []const T) []const T {
|
|
var begin: usize = 0;
|
|
while (begin < slice.len and indexOfScalar(T, values_to_strip, slice[begin]) != null) : (begin += 1) {}
|
|
return slice[begin..];
|
|
}
|
|
|
|
/// Remove a set of values from the end of a slice.
|
|
pub fn trimRight(comptime T: type, slice: []const T, values_to_strip: []const T) []const T {
|
|
var end: usize = slice.len;
|
|
while (end > 0 and indexOfScalar(T, values_to_strip, slice[end - 1]) != null) : (end -= 1) {}
|
|
return slice[0..end];
|
|
}
|
|
|
|
/// Remove a set of values from the beginning and end of a slice.
|
|
pub fn trim(comptime T: type, slice: []const T, values_to_strip: []const T) []const T {
|
|
var begin: usize = 0;
|
|
var end: usize = slice.len;
|
|
while (begin < end and indexOfScalar(T, values_to_strip, slice[begin]) != null) : (begin += 1) {}
|
|
while (end > begin and indexOfScalar(T, values_to_strip, slice[end - 1]) != null) : (end -= 1) {}
|
|
return slice[begin..end];
|
|
}
|
|
|
|
test trim {
|
|
try testing.expectEqualSlices(u8, "foo\n ", trimLeft(u8, " foo\n ", " \n"));
|
|
try testing.expectEqualSlices(u8, " foo", trimRight(u8, " foo\n ", " \n"));
|
|
try testing.expectEqualSlices(u8, "foo", trim(u8, " foo\n ", " \n"));
|
|
try testing.expectEqualSlices(u8, "foo", trim(u8, "foo", " \n"));
|
|
}
|
|
|
|
/// Linear search for the index of a scalar value inside a slice.
|
|
pub fn indexOfScalar(comptime T: type, slice: []const T, value: T) ?usize {
|
|
return indexOfScalarPos(T, slice, 0, value);
|
|
}
|
|
|
|
/// Linear search for the last index of a scalar value inside a slice.
|
|
pub fn lastIndexOfScalar(comptime T: type, slice: []const T, value: T) ?usize {
|
|
var i: usize = slice.len;
|
|
while (i != 0) {
|
|
i -= 1;
|
|
if (slice[i] == value) return i;
|
|
}
|
|
return null;
|
|
}
|
|
|
|
pub fn indexOfScalarPos(comptime T: type, slice: []const T, start_index: usize, value: T) ?usize {
|
|
if (start_index >= slice.len) return null;
|
|
|
|
var i: usize = start_index;
|
|
if (backend_supports_vectors and
|
|
!std.debug.inValgrind() and // https://github.com/ziglang/zig/issues/17717
|
|
!@inComptime() and
|
|
(@typeInfo(T) == .int or @typeInfo(T) == .float) and std.math.isPowerOfTwo(@bitSizeOf(T)))
|
|
{
|
|
if (std.simd.suggestVectorLength(T)) |block_len| {
|
|
// For Intel Nehalem (2009) and AMD Bulldozer (2012) or later, unaligned loads on aligned data result
|
|
// in the same execution as aligned loads. We ignore older arch's here and don't bother pre-aligning.
|
|
//
|
|
// Use `std.simd.suggestVectorLength(T)` to get the same alignment as used in this function
|
|
// however this usually isn't necessary unless your arch has a performance penalty due to this.
|
|
//
|
|
// This may differ for other arch's. Arm for example costs a cycle when loading across a cache
|
|
// line so explicit alignment prologues may be worth exploration.
|
|
|
|
// Unrolling here is ~10% improvement. We can then do one bounds check every 2 blocks
|
|
// instead of one which adds up.
|
|
const Block = @Vector(block_len, T);
|
|
if (i + 2 * block_len < slice.len) {
|
|
const mask: Block = @splat(value);
|
|
while (true) {
|
|
inline for (0..2) |_| {
|
|
const block: Block = slice[i..][0..block_len].*;
|
|
const matches = block == mask;
|
|
if (@reduce(.Or, matches)) {
|
|
return i + std.simd.firstTrue(matches).?;
|
|
}
|
|
i += block_len;
|
|
}
|
|
if (i + 2 * block_len >= slice.len) break;
|
|
}
|
|
}
|
|
|
|
// {block_len, block_len / 2} check
|
|
inline for (0..2) |j| {
|
|
const block_x_len = block_len / (1 << j);
|
|
comptime if (block_x_len < 4) break;
|
|
|
|
const BlockX = @Vector(block_x_len, T);
|
|
if (i + block_x_len < slice.len) {
|
|
const mask: BlockX = @splat(value);
|
|
const block: BlockX = slice[i..][0..block_x_len].*;
|
|
const matches = block == mask;
|
|
if (@reduce(.Or, matches)) {
|
|
return i + std.simd.firstTrue(matches).?;
|
|
}
|
|
i += block_x_len;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
for (slice[i..], i..) |c, j| {
|
|
if (c == value) return j;
|
|
}
|
|
return null;
|
|
}
|
|
|
|
test indexOfScalarPos {
|
|
const Types = [_]type{ u8, u16, u32, u64 };
|
|
|
|
inline for (Types) |T| {
|
|
var memory: [64 / @sizeOf(T)]T = undefined;
|
|
@memset(&memory, 0xaa);
|
|
memory[memory.len - 1] = 0;
|
|
|
|
for (0..memory.len) |i| {
|
|
try testing.expectEqual(memory.len - i - 1, indexOfScalarPos(T, memory[i..], 0, 0).?);
|
|
}
|
|
}
|
|
}
|
|
|
|
pub fn indexOfAny(comptime T: type, slice: []const T, values: []const T) ?usize {
|
|
return indexOfAnyPos(T, slice, 0, values);
|
|
}
|
|
|
|
pub fn lastIndexOfAny(comptime T: type, slice: []const T, values: []const T) ?usize {
|
|
var i: usize = slice.len;
|
|
while (i != 0) {
|
|
i -= 1;
|
|
for (values) |value| {
|
|
if (slice[i] == value) return i;
|
|
}
|
|
}
|
|
return null;
|
|
}
|
|
|
|
pub fn indexOfAnyPos(comptime T: type, slice: []const T, start_index: usize, values: []const T) ?usize {
|
|
if (start_index >= slice.len) return null;
|
|
for (slice[start_index..], start_index..) |c, i| {
|
|
for (values) |value| {
|
|
if (c == value) return i;
|
|
}
|
|
}
|
|
return null;
|
|
}
|
|
|
|
/// Find the first item in `slice` which is not contained in `values`.
|
|
///
|
|
/// Comparable to `strspn` in the C standard library.
|
|
pub fn indexOfNone(comptime T: type, slice: []const T, values: []const T) ?usize {
|
|
return indexOfNonePos(T, slice, 0, values);
|
|
}
|
|
|
|
/// Find the last item in `slice` which is not contained in `values`.
|
|
///
|
|
/// Like `strspn` in the C standard library, but searches from the end.
|
|
pub fn lastIndexOfNone(comptime T: type, slice: []const T, values: []const T) ?usize {
|
|
var i: usize = slice.len;
|
|
outer: while (i != 0) {
|
|
i -= 1;
|
|
for (values) |value| {
|
|
if (slice[i] == value) continue :outer;
|
|
}
|
|
return i;
|
|
}
|
|
return null;
|
|
}
|
|
|
|
/// Find the first item in `slice[start_index..]` which is not contained in `values`.
|
|
/// The returned index will be relative to the start of `slice`, and never less than `start_index`.
|
|
///
|
|
/// Comparable to `strspn` in the C standard library.
|
|
pub fn indexOfNonePos(comptime T: type, slice: []const T, start_index: usize, values: []const T) ?usize {
|
|
if (start_index >= slice.len) return null;
|
|
outer: for (slice[start_index..], start_index..) |c, i| {
|
|
for (values) |value| {
|
|
if (c == value) continue :outer;
|
|
}
|
|
return i;
|
|
}
|
|
return null;
|
|
}
|
|
|
|
test indexOfNone {
|
|
try testing.expect(indexOfNone(u8, "abc123", "123").? == 0);
|
|
try testing.expect(lastIndexOfNone(u8, "abc123", "123").? == 2);
|
|
try testing.expect(indexOfNone(u8, "123abc", "123").? == 3);
|
|
try testing.expect(lastIndexOfNone(u8, "123abc", "123").? == 5);
|
|
try testing.expect(indexOfNone(u8, "123123", "123") == null);
|
|
try testing.expect(indexOfNone(u8, "333333", "123") == null);
|
|
|
|
try testing.expect(indexOfNonePos(u8, "abc123", 3, "321") == null);
|
|
}
|
|
|
|
pub fn indexOf(comptime T: type, haystack: []const T, needle: []const T) ?usize {
|
|
return indexOfPos(T, haystack, 0, needle);
|
|
}
|
|
|
|
/// Find the index in a slice of a sub-slice, searching from the end backwards.
|
|
/// To start looking at a different index, slice the haystack first.
|
|
/// Consider using `lastIndexOf` instead of this, which will automatically use a
|
|
/// more sophisticated algorithm on larger inputs.
|
|
pub fn lastIndexOfLinear(comptime T: type, haystack: []const T, needle: []const T) ?usize {
|
|
var i: usize = haystack.len - needle.len;
|
|
while (true) : (i -= 1) {
|
|
if (mem.eql(T, haystack[i..][0..needle.len], needle)) return i;
|
|
if (i == 0) return null;
|
|
}
|
|
}
|
|
|
|
/// Consider using `indexOfPos` instead of this, which will automatically use a
|
|
/// more sophisticated algorithm on larger inputs.
|
|
pub fn indexOfPosLinear(comptime T: type, haystack: []const T, start_index: usize, needle: []const T) ?usize {
|
|
if (needle.len > haystack.len) return null;
|
|
var i: usize = start_index;
|
|
const end = haystack.len - needle.len;
|
|
while (i <= end) : (i += 1) {
|
|
if (eql(T, haystack[i..][0..needle.len], needle)) return i;
|
|
}
|
|
return null;
|
|
}
|
|
|
|
test indexOfPosLinear {
|
|
try testing.expectEqual(0, indexOfPosLinear(u8, "", 0, ""));
|
|
try testing.expectEqual(0, indexOfPosLinear(u8, "123", 0, ""));
|
|
|
|
try testing.expectEqual(null, indexOfPosLinear(u8, "", 0, "1"));
|
|
try testing.expectEqual(0, indexOfPosLinear(u8, "1", 0, "1"));
|
|
try testing.expectEqual(null, indexOfPosLinear(u8, "2", 0, "1"));
|
|
try testing.expectEqual(1, indexOfPosLinear(u8, "21", 0, "1"));
|
|
try testing.expectEqual(null, indexOfPosLinear(u8, "222", 0, "1"));
|
|
|
|
try testing.expectEqual(null, indexOfPosLinear(u8, "", 0, "12"));
|
|
try testing.expectEqual(null, indexOfPosLinear(u8, "1", 0, "12"));
|
|
try testing.expectEqual(null, indexOfPosLinear(u8, "2", 0, "12"));
|
|
try testing.expectEqual(0, indexOfPosLinear(u8, "12", 0, "12"));
|
|
try testing.expectEqual(null, indexOfPosLinear(u8, "21", 0, "12"));
|
|
try testing.expectEqual(1, indexOfPosLinear(u8, "212", 0, "12"));
|
|
try testing.expectEqual(0, indexOfPosLinear(u8, "122", 0, "12"));
|
|
try testing.expectEqual(1, indexOfPosLinear(u8, "212112", 0, "12"));
|
|
}
|
|
|
|
fn boyerMooreHorspoolPreprocessReverse(pattern: []const u8, table: *[256]usize) void {
|
|
for (table) |*c| {
|
|
c.* = pattern.len;
|
|
}
|
|
|
|
var i: usize = pattern.len - 1;
|
|
// The first item is intentionally ignored and the skip size will be pattern.len.
|
|
// This is the standard way Boyer-Moore-Horspool is implemented.
|
|
while (i > 0) : (i -= 1) {
|
|
table[pattern[i]] = i;
|
|
}
|
|
}
|
|
|
|
fn boyerMooreHorspoolPreprocess(pattern: []const u8, table: *[256]usize) void {
|
|
for (table) |*c| {
|
|
c.* = pattern.len;
|
|
}
|
|
|
|
var i: usize = 0;
|
|
// The last item is intentionally ignored and the skip size will be pattern.len.
|
|
// This is the standard way Boyer-Moore-Horspool is implemented.
|
|
while (i < pattern.len - 1) : (i += 1) {
|
|
table[pattern[i]] = pattern.len - 1 - i;
|
|
}
|
|
}
|
|
|
|
/// Find the index in a slice of a sub-slice, searching from the end backwards.
|
|
/// To start looking at a different index, slice the haystack first.
|
|
/// Uses the Reverse Boyer-Moore-Horspool algorithm on large inputs;
|
|
/// `lastIndexOfLinear` on small inputs.
|
|
pub fn lastIndexOf(comptime T: type, haystack: []const T, needle: []const T) ?usize {
|
|
if (needle.len > haystack.len) return null;
|
|
if (needle.len == 0) return haystack.len;
|
|
|
|
if (!std.meta.hasUniqueRepresentation(T) or haystack.len < 52 or needle.len <= 4)
|
|
return lastIndexOfLinear(T, haystack, needle);
|
|
|
|
const haystack_bytes = sliceAsBytes(haystack);
|
|
const needle_bytes = sliceAsBytes(needle);
|
|
|
|
var skip_table: [256]usize = undefined;
|
|
boyerMooreHorspoolPreprocessReverse(needle_bytes, skip_table[0..]);
|
|
|
|
var i: usize = haystack_bytes.len - needle_bytes.len;
|
|
while (true) {
|
|
if (i % @sizeOf(T) == 0 and mem.eql(u8, haystack_bytes[i .. i + needle_bytes.len], needle_bytes)) {
|
|
return @divExact(i, @sizeOf(T));
|
|
}
|
|
const skip = skip_table[haystack_bytes[i]];
|
|
if (skip > i) break;
|
|
i -= skip;
|
|
}
|
|
|
|
return null;
|
|
}
|
|
|
|
/// Uses Boyer-Moore-Horspool algorithm on large inputs; `indexOfPosLinear` on small inputs.
|
|
pub fn indexOfPos(comptime T: type, haystack: []const T, start_index: usize, needle: []const T) ?usize {
|
|
if (needle.len > haystack.len) return null;
|
|
if (needle.len < 2) {
|
|
if (needle.len == 0) return start_index;
|
|
// indexOfScalarPos is significantly faster than indexOfPosLinear
|
|
return indexOfScalarPos(T, haystack, start_index, needle[0]);
|
|
}
|
|
|
|
if (!std.meta.hasUniqueRepresentation(T) or haystack.len < 52 or needle.len <= 4)
|
|
return indexOfPosLinear(T, haystack, start_index, needle);
|
|
|
|
const haystack_bytes = sliceAsBytes(haystack);
|
|
const needle_bytes = sliceAsBytes(needle);
|
|
|
|
var skip_table: [256]usize = undefined;
|
|
boyerMooreHorspoolPreprocess(needle_bytes, skip_table[0..]);
|
|
|
|
var i: usize = start_index * @sizeOf(T);
|
|
while (i <= haystack_bytes.len - needle_bytes.len) {
|
|
if (i % @sizeOf(T) == 0 and mem.eql(u8, haystack_bytes[i .. i + needle_bytes.len], needle_bytes)) {
|
|
return @divExact(i, @sizeOf(T));
|
|
}
|
|
i += skip_table[haystack_bytes[i + needle_bytes.len - 1]];
|
|
}
|
|
|
|
return null;
|
|
}
|
|
|
|
test indexOf {
|
|
try testing.expect(indexOf(u8, "one two three four five six seven eight nine ten eleven", "three four").? == 8);
|
|
try testing.expect(lastIndexOf(u8, "one two three four five six seven eight nine ten eleven", "three four").? == 8);
|
|
try testing.expect(indexOf(u8, "one two three four five six seven eight nine ten eleven", "two two") == null);
|
|
try testing.expect(lastIndexOf(u8, "one two three four five six seven eight nine ten eleven", "two two") == null);
|
|
|
|
try testing.expect(indexOf(u8, "one two three four five six seven eight nine ten", "").? == 0);
|
|
try testing.expect(lastIndexOf(u8, "one two three four five six seven eight nine ten", "").? == 48);
|
|
|
|
try testing.expect(indexOf(u8, "one two three four", "four").? == 14);
|
|
try testing.expect(lastIndexOf(u8, "one two three two four", "two").? == 14);
|
|
try testing.expect(indexOf(u8, "one two three four", "gour") == null);
|
|
try testing.expect(lastIndexOf(u8, "one two three four", "gour") == null);
|
|
try testing.expect(indexOf(u8, "foo", "foo").? == 0);
|
|
try testing.expect(lastIndexOf(u8, "foo", "foo").? == 0);
|
|
try testing.expect(indexOf(u8, "foo", "fool") == null);
|
|
try testing.expect(lastIndexOf(u8, "foo", "lfoo") == null);
|
|
try testing.expect(lastIndexOf(u8, "foo", "fool") == null);
|
|
|
|
try testing.expect(indexOf(u8, "foo foo", "foo").? == 0);
|
|
try testing.expect(lastIndexOf(u8, "foo foo", "foo").? == 4);
|
|
try testing.expect(lastIndexOfAny(u8, "boo, cat", "abo").? == 6);
|
|
try testing.expect(lastIndexOfScalar(u8, "boo", 'o').? == 2);
|
|
}
|
|
|
|
test "indexOf multibyte" {
|
|
{
|
|
// make haystack and needle long enough to trigger Boyer-Moore-Horspool algorithm
|
|
const haystack = [1]u16{0} ** 100 ++ [_]u16{ 0xbbaa, 0xccbb, 0xddcc, 0xeedd, 0xffee, 0x00ff };
|
|
const needle = [_]u16{ 0xbbaa, 0xccbb, 0xddcc, 0xeedd, 0xffee };
|
|
try testing.expectEqual(indexOfPos(u16, &haystack, 0, &needle), 100);
|
|
|
|
// check for misaligned false positives (little and big endian)
|
|
const needleLE = [_]u16{ 0xbbbb, 0xcccc, 0xdddd, 0xeeee, 0xffff };
|
|
try testing.expectEqual(indexOfPos(u16, &haystack, 0, &needleLE), null);
|
|
const needleBE = [_]u16{ 0xaacc, 0xbbdd, 0xccee, 0xddff, 0xee00 };
|
|
try testing.expectEqual(indexOfPos(u16, &haystack, 0, &needleBE), null);
|
|
}
|
|
|
|
{
|
|
// make haystack and needle long enough to trigger Boyer-Moore-Horspool algorithm
|
|
const haystack = [_]u16{ 0xbbaa, 0xccbb, 0xddcc, 0xeedd, 0xffee, 0x00ff } ++ [1]u16{0} ** 100;
|
|
const needle = [_]u16{ 0xbbaa, 0xccbb, 0xddcc, 0xeedd, 0xffee };
|
|
try testing.expectEqual(lastIndexOf(u16, &haystack, &needle), 0);
|
|
|
|
// check for misaligned false positives (little and big endian)
|
|
const needleLE = [_]u16{ 0xbbbb, 0xcccc, 0xdddd, 0xeeee, 0xffff };
|
|
try testing.expectEqual(lastIndexOf(u16, &haystack, &needleLE), null);
|
|
const needleBE = [_]u16{ 0xaacc, 0xbbdd, 0xccee, 0xddff, 0xee00 };
|
|
try testing.expectEqual(lastIndexOf(u16, &haystack, &needleBE), null);
|
|
}
|
|
}
|
|
|
|
test "indexOfPos empty needle" {
|
|
try testing.expectEqual(indexOfPos(u8, "abracadabra", 5, ""), 5);
|
|
}
|
|
|
|
/// Returns the number of needles inside the haystack
|
|
/// needle.len must be > 0
|
|
/// does not count overlapping needles
|
|
pub fn count(comptime T: type, haystack: []const T, needle: []const T) usize {
|
|
assert(needle.len > 0);
|
|
var i: usize = 0;
|
|
var found: usize = 0;
|
|
|
|
while (indexOfPos(T, haystack, i, needle)) |idx| {
|
|
i = idx + needle.len;
|
|
found += 1;
|
|
}
|
|
|
|
return found;
|
|
}
|
|
|
|
test count {
|
|
try testing.expect(count(u8, "", "h") == 0);
|
|
try testing.expect(count(u8, "h", "h") == 1);
|
|
try testing.expect(count(u8, "hh", "h") == 2);
|
|
try testing.expect(count(u8, "world!", "hello") == 0);
|
|
try testing.expect(count(u8, "hello world!", "hello") == 1);
|
|
try testing.expect(count(u8, " abcabc abc", "abc") == 3);
|
|
try testing.expect(count(u8, "udexdcbvbruhasdrw", "bruh") == 1);
|
|
try testing.expect(count(u8, "foo bar", "o bar") == 1);
|
|
try testing.expect(count(u8, "foofoofoo", "foo") == 3);
|
|
try testing.expect(count(u8, "fffffff", "ff") == 3);
|
|
try testing.expect(count(u8, "owowowu", "owowu") == 1);
|
|
}
|
|
|
|
/// Returns true if the haystack contains expected_count or more needles
|
|
/// needle.len must be > 0
|
|
/// does not count overlapping needles
|
|
pub fn containsAtLeast(comptime T: type, haystack: []const T, expected_count: usize, needle: []const T) bool {
|
|
assert(needle.len > 0);
|
|
if (expected_count == 0) return true;
|
|
|
|
var i: usize = 0;
|
|
var found: usize = 0;
|
|
|
|
while (indexOfPos(T, haystack, i, needle)) |idx| {
|
|
i = idx + needle.len;
|
|
found += 1;
|
|
if (found == expected_count) return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
test containsAtLeast {
|
|
try testing.expect(containsAtLeast(u8, "aa", 0, "a"));
|
|
try testing.expect(containsAtLeast(u8, "aa", 1, "a"));
|
|
try testing.expect(containsAtLeast(u8, "aa", 2, "a"));
|
|
try testing.expect(!containsAtLeast(u8, "aa", 3, "a"));
|
|
|
|
try testing.expect(containsAtLeast(u8, "radaradar", 1, "radar"));
|
|
try testing.expect(!containsAtLeast(u8, "radaradar", 2, "radar"));
|
|
|
|
try testing.expect(containsAtLeast(u8, "radarradaradarradar", 3, "radar"));
|
|
try testing.expect(!containsAtLeast(u8, "radarradaradarradar", 4, "radar"));
|
|
|
|
try testing.expect(containsAtLeast(u8, " radar radar ", 2, "radar"));
|
|
try testing.expect(!containsAtLeast(u8, " radar radar ", 3, "radar"));
|
|
}
|
|
|
|
/// Reads an integer from memory with size equal to bytes.len.
|
|
/// T specifies the return type, which must be large enough to store
|
|
/// the result.
|
|
pub fn readVarInt(comptime ReturnType: type, bytes: []const u8, endian: Endian) ReturnType {
|
|
assert(@typeInfo(ReturnType).int.bits >= bytes.len * 8);
|
|
const bits = @typeInfo(ReturnType).int.bits;
|
|
const signedness = @typeInfo(ReturnType).int.signedness;
|
|
const WorkType = std.meta.Int(signedness, @max(16, bits));
|
|
var result: WorkType = 0;
|
|
switch (endian) {
|
|
.big => {
|
|
for (bytes) |b| {
|
|
result = (result << 8) | b;
|
|
}
|
|
},
|
|
.little => {
|
|
const ShiftType = math.Log2Int(WorkType);
|
|
for (bytes, 0..) |b, index| {
|
|
result = result | (@as(WorkType, b) << @as(ShiftType, @intCast(index * 8)));
|
|
}
|
|
},
|
|
}
|
|
return @as(ReturnType, @truncate(result));
|
|
}
|
|
|
|
test readVarInt {
|
|
try testing.expect(readVarInt(u0, &[_]u8{}, .big) == 0x0);
|
|
try testing.expect(readVarInt(u0, &[_]u8{}, .little) == 0x0);
|
|
try testing.expect(readVarInt(u8, &[_]u8{0x12}, .big) == 0x12);
|
|
try testing.expect(readVarInt(u8, &[_]u8{0xde}, .little) == 0xde);
|
|
try testing.expect(readVarInt(u16, &[_]u8{ 0x12, 0x34 }, .big) == 0x1234);
|
|
try testing.expect(readVarInt(u16, &[_]u8{ 0x12, 0x34 }, .little) == 0x3412);
|
|
|
|
try testing.expect(readVarInt(i8, &[_]u8{0xff}, .big) == -1);
|
|
try testing.expect(readVarInt(i8, &[_]u8{0xfe}, .little) == -2);
|
|
try testing.expect(readVarInt(i16, &[_]u8{ 0xff, 0xfd }, .big) == -3);
|
|
try testing.expect(readVarInt(i16, &[_]u8{ 0xfc, 0xff }, .little) == -4);
|
|
|
|
// Return type can be oversized (bytes.len * 8 < @typeInfo(ReturnType).int.bits)
|
|
try testing.expect(readVarInt(u9, &[_]u8{0x12}, .little) == 0x12);
|
|
try testing.expect(readVarInt(u9, &[_]u8{0xde}, .big) == 0xde);
|
|
try testing.expect(readVarInt(u80, &[_]u8{ 0x12, 0x34, 0x56, 0x78, 0x9a, 0xbc, 0xde, 0xf0, 0x24 }, .big) == 0x123456789abcdef024);
|
|
try testing.expect(readVarInt(u80, &[_]u8{ 0xec, 0x10, 0x32, 0x54, 0x76, 0x98, 0xba, 0xdc, 0xfe }, .little) == 0xfedcba9876543210ec);
|
|
|
|
try testing.expect(readVarInt(i9, &[_]u8{0xff}, .big) == 0xff);
|
|
try testing.expect(readVarInt(i9, &[_]u8{0xfe}, .little) == 0xfe);
|
|
}
|
|
|
|
/// Loads an integer from packed memory with provided bit_count, bit_offset, and signedness.
|
|
/// Asserts that T is large enough to store the read value.
|
|
pub fn readVarPackedInt(
|
|
comptime T: type,
|
|
bytes: []const u8,
|
|
bit_offset: usize,
|
|
bit_count: usize,
|
|
endian: std.builtin.Endian,
|
|
signedness: std.builtin.Signedness,
|
|
) T {
|
|
const uN = std.meta.Int(.unsigned, @bitSizeOf(T));
|
|
const iN = std.meta.Int(.signed, @bitSizeOf(T));
|
|
const Log2N = std.math.Log2Int(T);
|
|
|
|
const read_size = (bit_count + (bit_offset % 8) + 7) / 8;
|
|
const bit_shift = @as(u3, @intCast(bit_offset % 8));
|
|
const pad = @as(Log2N, @intCast(@bitSizeOf(T) - bit_count));
|
|
|
|
const lowest_byte = switch (endian) {
|
|
.big => bytes.len - (bit_offset / 8) - read_size,
|
|
.little => bit_offset / 8,
|
|
};
|
|
const read_bytes = bytes[lowest_byte..][0..read_size];
|
|
|
|
if (@bitSizeOf(T) <= 8) {
|
|
// These are the same shifts/masks we perform below, but adds `@truncate`/`@intCast`
|
|
// where needed since int is smaller than a byte.
|
|
const value = if (read_size == 1) b: {
|
|
break :b @as(uN, @truncate(read_bytes[0] >> bit_shift));
|
|
} else b: {
|
|
const i: u1 = @intFromBool(endian == .big);
|
|
const head = @as(uN, @truncate(read_bytes[i] >> bit_shift));
|
|
const tail_shift = @as(Log2N, @intCast(@as(u4, 8) - bit_shift));
|
|
const tail = @as(uN, @truncate(read_bytes[1 - i]));
|
|
break :b (tail << tail_shift) | head;
|
|
};
|
|
switch (signedness) {
|
|
.signed => return @as(T, @intCast((@as(iN, @bitCast(value)) << pad) >> pad)),
|
|
.unsigned => return @as(T, @intCast((@as(uN, @bitCast(value)) << pad) >> pad)),
|
|
}
|
|
}
|
|
|
|
// Copy the value out (respecting endianness), accounting for bit_shift
|
|
var int: uN = 0;
|
|
switch (endian) {
|
|
.big => {
|
|
for (read_bytes[0 .. read_size - 1]) |elem| {
|
|
int = elem | (int << 8);
|
|
}
|
|
int = (read_bytes[read_size - 1] >> bit_shift) | (int << (@as(u4, 8) - bit_shift));
|
|
},
|
|
.little => {
|
|
int = read_bytes[0] >> bit_shift;
|
|
for (read_bytes[1..], 0..) |elem, i| {
|
|
int |= (@as(uN, elem) << @as(Log2N, @intCast((8 * (i + 1) - bit_shift))));
|
|
}
|
|
},
|
|
}
|
|
switch (signedness) {
|
|
.signed => return @as(T, @intCast((@as(iN, @bitCast(int)) << pad) >> pad)),
|
|
.unsigned => return @as(T, @intCast((@as(uN, @bitCast(int)) << pad) >> pad)),
|
|
}
|
|
}
|
|
|
|
test readVarPackedInt {
|
|
const T = packed struct(u16) { a: u3, b: u7, c: u6 };
|
|
var st = T{ .a = 1, .b = 2, .c = 4 };
|
|
const b_field = readVarPackedInt(u64, std.mem.asBytes(&st), @bitOffsetOf(T, "b"), 7, builtin.cpu.arch.endian(), .unsigned);
|
|
try std.testing.expectEqual(st.b, b_field);
|
|
}
|
|
|
|
/// Reads an integer from memory with bit count specified by T.
|
|
/// The bit count of T must be evenly divisible by 8.
|
|
/// This function cannot fail and cannot cause undefined behavior.
|
|
pub inline fn readInt(comptime T: type, buffer: *const [@divExact(@typeInfo(T).int.bits, 8)]u8, endian: Endian) T {
|
|
const value: T = @bitCast(buffer.*);
|
|
return if (endian == native_endian) value else @byteSwap(value);
|
|
}
|
|
|
|
test readInt {
|
|
try testing.expect(readInt(u0, &[_]u8{}, .big) == 0x0);
|
|
try testing.expect(readInt(u0, &[_]u8{}, .little) == 0x0);
|
|
|
|
try testing.expect(readInt(u8, &[_]u8{0x32}, .big) == 0x32);
|
|
try testing.expect(readInt(u8, &[_]u8{0x12}, .little) == 0x12);
|
|
|
|
try testing.expect(readInt(u16, &[_]u8{ 0x12, 0x34 }, .big) == 0x1234);
|
|
try testing.expect(readInt(u16, &[_]u8{ 0x12, 0x34 }, .little) == 0x3412);
|
|
|
|
try testing.expect(readInt(u72, &[_]u8{ 0x12, 0x34, 0x56, 0x78, 0x9a, 0xbc, 0xde, 0xf0, 0x24 }, .big) == 0x123456789abcdef024);
|
|
try testing.expect(readInt(u72, &[_]u8{ 0xec, 0x10, 0x32, 0x54, 0x76, 0x98, 0xba, 0xdc, 0xfe }, .little) == 0xfedcba9876543210ec);
|
|
|
|
try testing.expect(readInt(i8, &[_]u8{0xff}, .big) == -1);
|
|
try testing.expect(readInt(i8, &[_]u8{0xfe}, .little) == -2);
|
|
|
|
try testing.expect(readInt(i16, &[_]u8{ 0xff, 0xfd }, .big) == -3);
|
|
try testing.expect(readInt(i16, &[_]u8{ 0xfc, 0xff }, .little) == -4);
|
|
|
|
try moreReadIntTests();
|
|
try comptime moreReadIntTests();
|
|
}
|
|
|
|
fn readPackedIntLittle(comptime T: type, bytes: []const u8, bit_offset: usize) T {
|
|
const uN = std.meta.Int(.unsigned, @bitSizeOf(T));
|
|
const Log2N = std.math.Log2Int(T);
|
|
|
|
const bit_count = @as(usize, @bitSizeOf(T));
|
|
const bit_shift = @as(u3, @intCast(bit_offset % 8));
|
|
|
|
const load_size = (bit_count + 7) / 8;
|
|
const load_tail_bits = @as(u3, @intCast((load_size * 8) - bit_count));
|
|
const LoadInt = std.meta.Int(.unsigned, load_size * 8);
|
|
|
|
if (bit_count == 0)
|
|
return 0;
|
|
|
|
// Read by loading a LoadInt, and then follow it up with a 1-byte read
|
|
// of the tail if bit_offset pushed us over a byte boundary.
|
|
const read_bytes = bytes[bit_offset / 8 ..];
|
|
const val = @as(uN, @truncate(readInt(LoadInt, read_bytes[0..load_size], .little) >> bit_shift));
|
|
if (bit_shift > load_tail_bits) {
|
|
const tail_bits = @as(Log2N, @intCast(bit_shift - load_tail_bits));
|
|
const tail_byte = read_bytes[load_size];
|
|
const tail_truncated = if (bit_count < 8) @as(uN, @truncate(tail_byte)) else @as(uN, tail_byte);
|
|
return @as(T, @bitCast(val | (tail_truncated << (@as(Log2N, @truncate(bit_count)) -% tail_bits))));
|
|
} else return @as(T, @bitCast(val));
|
|
}
|
|
|
|
fn readPackedIntBig(comptime T: type, bytes: []const u8, bit_offset: usize) T {
|
|
const uN = std.meta.Int(.unsigned, @bitSizeOf(T));
|
|
const Log2N = std.math.Log2Int(T);
|
|
|
|
const bit_count = @as(usize, @bitSizeOf(T));
|
|
const bit_shift = @as(u3, @intCast(bit_offset % 8));
|
|
const byte_count = (@as(usize, bit_shift) + bit_count + 7) / 8;
|
|
|
|
const load_size = (bit_count + 7) / 8;
|
|
const load_tail_bits = @as(u3, @intCast((load_size * 8) - bit_count));
|
|
const LoadInt = std.meta.Int(.unsigned, load_size * 8);
|
|
|
|
if (bit_count == 0)
|
|
return 0;
|
|
|
|
// Read by loading a LoadInt, and then follow it up with a 1-byte read
|
|
// of the tail if bit_offset pushed us over a byte boundary.
|
|
const end = bytes.len - (bit_offset / 8);
|
|
const read_bytes = bytes[(end - byte_count)..end];
|
|
const val = @as(uN, @truncate(readInt(LoadInt, bytes[(end - load_size)..end][0..load_size], .big) >> bit_shift));
|
|
if (bit_shift > load_tail_bits) {
|
|
const tail_bits = @as(Log2N, @intCast(bit_shift - load_tail_bits));
|
|
const tail_byte = if (bit_count < 8) @as(uN, @truncate(read_bytes[0])) else @as(uN, read_bytes[0]);
|
|
return @as(T, @bitCast(val | (tail_byte << (@as(Log2N, @truncate(bit_count)) -% tail_bits))));
|
|
} else return @as(T, @bitCast(val));
|
|
}
|
|
|
|
pub const readPackedIntNative = switch (native_endian) {
|
|
.little => readPackedIntLittle,
|
|
.big => readPackedIntBig,
|
|
};
|
|
|
|
pub const readPackedIntForeign = switch (native_endian) {
|
|
.little => readPackedIntBig,
|
|
.big => readPackedIntLittle,
|
|
};
|
|
|
|
/// Loads an integer from packed memory.
|
|
/// Asserts that buffer contains at least bit_offset + @bitSizeOf(T) bits.
|
|
pub fn readPackedInt(comptime T: type, bytes: []const u8, bit_offset: usize, endian: Endian) T {
|
|
switch (endian) {
|
|
.little => return readPackedIntLittle(T, bytes, bit_offset),
|
|
.big => return readPackedIntBig(T, bytes, bit_offset),
|
|
}
|
|
}
|
|
|
|
test readPackedInt {
|
|
const T = packed struct(u16) { a: u3, b: u7, c: u6 };
|
|
var st = T{ .a = 1, .b = 2, .c = 4 };
|
|
const b_field = readPackedInt(u7, std.mem.asBytes(&st), @bitOffsetOf(T, "b"), builtin.cpu.arch.endian());
|
|
try std.testing.expectEqual(st.b, b_field);
|
|
}
|
|
|
|
test "comptime read/write int" {
|
|
comptime {
|
|
var bytes: [2]u8 = undefined;
|
|
writeInt(u16, &bytes, 0x1234, .little);
|
|
const result = readInt(u16, &bytes, .big);
|
|
try testing.expect(result == 0x3412);
|
|
}
|
|
comptime {
|
|
var bytes: [2]u8 = undefined;
|
|
writeInt(u16, &bytes, 0x1234, .big);
|
|
const result = readInt(u16, &bytes, .little);
|
|
try testing.expect(result == 0x3412);
|
|
}
|
|
}
|
|
|
|
/// Writes an integer to memory, storing it in twos-complement.
|
|
/// This function always succeeds, has defined behavior for all inputs, but
|
|
/// the integer bit width must be divisible by 8.
|
|
pub inline fn writeInt(comptime T: type, buffer: *[@divExact(@typeInfo(T).int.bits, 8)]u8, value: T, endian: Endian) void {
|
|
buffer.* = @bitCast(if (endian == native_endian) value else @byteSwap(value));
|
|
}
|
|
|
|
test writeInt {
|
|
var buf0: [0]u8 = undefined;
|
|
var buf1: [1]u8 = undefined;
|
|
var buf2: [2]u8 = undefined;
|
|
var buf9: [9]u8 = undefined;
|
|
|
|
writeInt(u0, &buf0, 0x0, .big);
|
|
try testing.expect(eql(u8, buf0[0..], &[_]u8{}));
|
|
writeInt(u0, &buf0, 0x0, .little);
|
|
try testing.expect(eql(u8, buf0[0..], &[_]u8{}));
|
|
|
|
writeInt(u8, &buf1, 0x12, .big);
|
|
try testing.expect(eql(u8, buf1[0..], &[_]u8{0x12}));
|
|
writeInt(u8, &buf1, 0x34, .little);
|
|
try testing.expect(eql(u8, buf1[0..], &[_]u8{0x34}));
|
|
|
|
writeInt(u16, &buf2, 0x1234, .big);
|
|
try testing.expect(eql(u8, buf2[0..], &[_]u8{ 0x12, 0x34 }));
|
|
writeInt(u16, &buf2, 0x5678, .little);
|
|
try testing.expect(eql(u8, buf2[0..], &[_]u8{ 0x78, 0x56 }));
|
|
|
|
writeInt(u72, &buf9, 0x123456789abcdef024, .big);
|
|
try testing.expect(eql(u8, buf9[0..], &[_]u8{ 0x12, 0x34, 0x56, 0x78, 0x9a, 0xbc, 0xde, 0xf0, 0x24 }));
|
|
writeInt(u72, &buf9, 0xfedcba9876543210ec, .little);
|
|
try testing.expect(eql(u8, buf9[0..], &[_]u8{ 0xec, 0x10, 0x32, 0x54, 0x76, 0x98, 0xba, 0xdc, 0xfe }));
|
|
|
|
writeInt(i8, &buf1, -1, .big);
|
|
try testing.expect(eql(u8, buf1[0..], &[_]u8{0xff}));
|
|
writeInt(i8, &buf1, -2, .little);
|
|
try testing.expect(eql(u8, buf1[0..], &[_]u8{0xfe}));
|
|
|
|
writeInt(i16, &buf2, -3, .big);
|
|
try testing.expect(eql(u8, buf2[0..], &[_]u8{ 0xff, 0xfd }));
|
|
writeInt(i16, &buf2, -4, .little);
|
|
try testing.expect(eql(u8, buf2[0..], &[_]u8{ 0xfc, 0xff }));
|
|
}
|
|
|
|
fn writePackedIntLittle(comptime T: type, bytes: []u8, bit_offset: usize, value: T) void {
|
|
const uN = std.meta.Int(.unsigned, @bitSizeOf(T));
|
|
const Log2N = std.math.Log2Int(T);
|
|
|
|
const bit_count = @as(usize, @bitSizeOf(T));
|
|
const bit_shift = @as(u3, @intCast(bit_offset % 8));
|
|
|
|
const store_size = (@bitSizeOf(T) + 7) / 8;
|
|
const store_tail_bits = @as(u3, @intCast((store_size * 8) - bit_count));
|
|
const StoreInt = std.meta.Int(.unsigned, store_size * 8);
|
|
|
|
if (bit_count == 0)
|
|
return;
|
|
|
|
// Write by storing a StoreInt, and then follow it up with a 1-byte tail
|
|
// if bit_offset pushed us over a byte boundary.
|
|
const write_bytes = bytes[bit_offset / 8 ..];
|
|
const head = write_bytes[0] & ((@as(u8, 1) << bit_shift) - 1);
|
|
|
|
var write_value = (@as(StoreInt, @as(uN, @bitCast(value))) << bit_shift) | @as(StoreInt, @intCast(head));
|
|
if (bit_shift > store_tail_bits) {
|
|
const tail_len = @as(Log2N, @intCast(bit_shift - store_tail_bits));
|
|
write_bytes[store_size] &= ~((@as(u8, 1) << @as(u3, @intCast(tail_len))) - 1);
|
|
write_bytes[store_size] |= @as(u8, @intCast((@as(uN, @bitCast(value)) >> (@as(Log2N, @truncate(bit_count)) -% tail_len))));
|
|
} else if (bit_shift < store_tail_bits) {
|
|
const tail_len = store_tail_bits - bit_shift;
|
|
const tail = write_bytes[store_size - 1] & (@as(u8, 0xfe) << (7 - tail_len));
|
|
write_value |= @as(StoreInt, tail) << (8 * (store_size - 1));
|
|
}
|
|
|
|
writeInt(StoreInt, write_bytes[0..store_size], write_value, .little);
|
|
}
|
|
|
|
fn writePackedIntBig(comptime T: type, bytes: []u8, bit_offset: usize, value: T) void {
|
|
const uN = std.meta.Int(.unsigned, @bitSizeOf(T));
|
|
const Log2N = std.math.Log2Int(T);
|
|
|
|
const bit_count = @as(usize, @bitSizeOf(T));
|
|
const bit_shift = @as(u3, @intCast(bit_offset % 8));
|
|
const byte_count = (bit_shift + bit_count + 7) / 8;
|
|
|
|
const store_size = (@bitSizeOf(T) + 7) / 8;
|
|
const store_tail_bits = @as(u3, @intCast((store_size * 8) - bit_count));
|
|
const StoreInt = std.meta.Int(.unsigned, store_size * 8);
|
|
|
|
if (bit_count == 0)
|
|
return;
|
|
|
|
// Write by storing a StoreInt, and then follow it up with a 1-byte tail
|
|
// if bit_offset pushed us over a byte boundary.
|
|
const end = bytes.len - (bit_offset / 8);
|
|
const write_bytes = bytes[(end - byte_count)..end];
|
|
const head = write_bytes[byte_count - 1] & ((@as(u8, 1) << bit_shift) - 1);
|
|
|
|
var write_value = (@as(StoreInt, @as(uN, @bitCast(value))) << bit_shift) | @as(StoreInt, @intCast(head));
|
|
if (bit_shift > store_tail_bits) {
|
|
const tail_len = @as(Log2N, @intCast(bit_shift - store_tail_bits));
|
|
write_bytes[0] &= ~((@as(u8, 1) << @as(u3, @intCast(tail_len))) - 1);
|
|
write_bytes[0] |= @as(u8, @intCast((@as(uN, @bitCast(value)) >> (@as(Log2N, @truncate(bit_count)) -% tail_len))));
|
|
} else if (bit_shift < store_tail_bits) {
|
|
const tail_len = store_tail_bits - bit_shift;
|
|
const tail = write_bytes[0] & (@as(u8, 0xfe) << (7 - tail_len));
|
|
write_value |= @as(StoreInt, tail) << (8 * (store_size - 1));
|
|
}
|
|
|
|
writeInt(StoreInt, write_bytes[(byte_count - store_size)..][0..store_size], write_value, .big);
|
|
}
|
|
|
|
pub const writePackedIntNative = switch (native_endian) {
|
|
.little => writePackedIntLittle,
|
|
.big => writePackedIntBig,
|
|
};
|
|
|
|
pub const writePackedIntForeign = switch (native_endian) {
|
|
.little => writePackedIntBig,
|
|
.big => writePackedIntLittle,
|
|
};
|
|
|
|
/// Stores an integer to packed memory.
|
|
/// Asserts that buffer contains at least bit_offset + @bitSizeOf(T) bits.
|
|
pub fn writePackedInt(comptime T: type, bytes: []u8, bit_offset: usize, value: T, endian: Endian) void {
|
|
switch (endian) {
|
|
.little => writePackedIntLittle(T, bytes, bit_offset, value),
|
|
.big => writePackedIntBig(T, bytes, bit_offset, value),
|
|
}
|
|
}
|
|
|
|
test writePackedInt {
|
|
const T = packed struct(u16) { a: u3, b: u7, c: u6 };
|
|
var st = T{ .a = 1, .b = 2, .c = 4 };
|
|
writePackedInt(u7, std.mem.asBytes(&st), @bitOffsetOf(T, "b"), 0x7f, builtin.cpu.arch.endian());
|
|
try std.testing.expectEqual(T{ .a = 1, .b = 0x7f, .c = 4 }, st);
|
|
}
|
|
|
|
/// Stores an integer to packed memory with provided bit_offset, bit_count, and signedness.
|
|
/// If negative, the written value is sign-extended.
|
|
pub fn writeVarPackedInt(bytes: []u8, bit_offset: usize, bit_count: usize, value: anytype, endian: std.builtin.Endian) void {
|
|
const T = @TypeOf(value);
|
|
const uN = std.meta.Int(.unsigned, @bitSizeOf(T));
|
|
|
|
const bit_shift = @as(u3, @intCast(bit_offset % 8));
|
|
const write_size = (bit_count + bit_shift + 7) / 8;
|
|
const lowest_byte = switch (endian) {
|
|
.big => bytes.len - (bit_offset / 8) - write_size,
|
|
.little => bit_offset / 8,
|
|
};
|
|
const write_bytes = bytes[lowest_byte..][0..write_size];
|
|
|
|
if (write_size == 0) {
|
|
return;
|
|
} else if (write_size == 1) {
|
|
// Single byte writes are handled specially, since we need to mask bits
|
|
// on both ends of the byte.
|
|
const mask = (@as(u8, 0xff) >> @as(u3, @intCast(8 - bit_count)));
|
|
const new_bits = @as(u8, @intCast(@as(uN, @bitCast(value)) & mask)) << bit_shift;
|
|
write_bytes[0] = (write_bytes[0] & ~(mask << bit_shift)) | new_bits;
|
|
return;
|
|
}
|
|
|
|
var remaining: T = value;
|
|
|
|
// Iterate bytes forward for Little-endian, backward for Big-endian
|
|
const delta: i2 = if (endian == .big) -1 else 1;
|
|
const start = if (endian == .big) @as(isize, @intCast(write_bytes.len - 1)) else 0;
|
|
|
|
var i: isize = start; // isize for signed index arithmetic
|
|
|
|
// Write first byte, using a mask to protects bits preceding bit_offset
|
|
const head_mask = @as(u8, 0xff) >> bit_shift;
|
|
write_bytes[@intCast(i)] &= ~(head_mask << bit_shift);
|
|
write_bytes[@intCast(i)] |= @as(u8, @intCast(@as(uN, @bitCast(remaining)) & head_mask)) << bit_shift;
|
|
remaining = math.shr(T, remaining, @as(u4, 8) - bit_shift);
|
|
i += delta;
|
|
|
|
// Write bytes[1..bytes.len - 1]
|
|
if (@bitSizeOf(T) > 8) {
|
|
const loop_end = start + delta * (@as(isize, @intCast(write_size)) - 1);
|
|
while (i != loop_end) : (i += delta) {
|
|
write_bytes[@as(usize, @intCast(i))] = @as(u8, @truncate(@as(uN, @bitCast(remaining))));
|
|
remaining >>= 8;
|
|
}
|
|
}
|
|
|
|
// Write last byte, using a mask to protect bits following bit_offset + bit_count
|
|
const following_bits = -%@as(u3, @truncate(bit_shift + bit_count));
|
|
const tail_mask = (@as(u8, 0xff) << following_bits) >> following_bits;
|
|
write_bytes[@as(usize, @intCast(i))] &= ~tail_mask;
|
|
write_bytes[@as(usize, @intCast(i))] |= @as(u8, @intCast(@as(uN, @bitCast(remaining)) & tail_mask));
|
|
}
|
|
|
|
test writeVarPackedInt {
|
|
const T = packed struct(u16) { a: u3, b: u7, c: u6 };
|
|
var st = T{ .a = 1, .b = 2, .c = 4 };
|
|
const value: u64 = 0x7f;
|
|
writeVarPackedInt(std.mem.asBytes(&st), @bitOffsetOf(T, "b"), 7, value, builtin.cpu.arch.endian());
|
|
try testing.expectEqual(T{ .a = 1, .b = value, .c = 4 }, st);
|
|
}
|
|
|
|
/// Swap the byte order of all the members of the fields of a struct
|
|
/// (Changing their endianness)
|
|
pub fn byteSwapAllFields(comptime S: type, ptr: *S) void {
|
|
switch (@typeInfo(S)) {
|
|
.@"struct" => {
|
|
inline for (std.meta.fields(S)) |f| {
|
|
switch (@typeInfo(f.type)) {
|
|
.@"struct" => |struct_info| if (struct_info.backing_integer) |Int| {
|
|
@field(ptr, f.name) = @bitCast(@byteSwap(@as(Int, @bitCast(@field(ptr, f.name)))));
|
|
} else {
|
|
byteSwapAllFields(f.type, &@field(ptr, f.name));
|
|
},
|
|
.array => byteSwapAllFields(f.type, &@field(ptr, f.name)),
|
|
.@"enum" => {
|
|
@field(ptr, f.name) = @enumFromInt(@byteSwap(@intFromEnum(@field(ptr, f.name))));
|
|
},
|
|
.bool => {},
|
|
.float => |float_info| {
|
|
@field(ptr, f.name) = @bitCast(@byteSwap(@as(std.meta.Int(.unsigned, float_info.bits), @bitCast(@field(ptr, f.name)))));
|
|
},
|
|
else => {
|
|
@field(ptr, f.name) = @byteSwap(@field(ptr, f.name));
|
|
},
|
|
}
|
|
}
|
|
},
|
|
.array => {
|
|
for (ptr) |*item| {
|
|
switch (@typeInfo(@TypeOf(item.*))) {
|
|
.@"struct", .array => byteSwapAllFields(@TypeOf(item.*), item),
|
|
.@"enum" => {
|
|
item.* = @enumFromInt(@byteSwap(@intFromEnum(item.*)));
|
|
},
|
|
.bool => {},
|
|
.float => |float_info| {
|
|
item.* = @bitCast(@byteSwap(@as(std.meta.Int(.unsigned, float_info.bits), @bitCast(item.*))));
|
|
},
|
|
else => {
|
|
item.* = @byteSwap(item.*);
|
|
},
|
|
}
|
|
}
|
|
},
|
|
else => @compileError("byteSwapAllFields expects a struct or array as the first argument"),
|
|
}
|
|
}
|
|
|
|
test byteSwapAllFields {
|
|
const T = extern struct {
|
|
f0: u8,
|
|
f1: u16,
|
|
f2: u32,
|
|
f3: [1]u8,
|
|
f4: bool,
|
|
f5: f32,
|
|
};
|
|
const K = extern struct {
|
|
f0: u8,
|
|
f1: T,
|
|
f2: u16,
|
|
f3: [1]u8,
|
|
f4: bool,
|
|
f5: f32,
|
|
};
|
|
var s = T{
|
|
.f0 = 0x12,
|
|
.f1 = 0x1234,
|
|
.f2 = 0x12345678,
|
|
.f3 = .{0x12},
|
|
.f4 = true,
|
|
.f5 = @as(f32, @bitCast(@as(u32, 0x4640e400))),
|
|
};
|
|
var k = K{
|
|
.f0 = 0x12,
|
|
.f1 = s,
|
|
.f2 = 0x1234,
|
|
.f3 = .{0x12},
|
|
.f4 = false,
|
|
.f5 = @as(f32, @bitCast(@as(u32, 0x45d42800))),
|
|
};
|
|
byteSwapAllFields(T, &s);
|
|
byteSwapAllFields(K, &k);
|
|
try std.testing.expectEqual(T{
|
|
.f0 = 0x12,
|
|
.f1 = 0x3412,
|
|
.f2 = 0x78563412,
|
|
.f3 = .{0x12},
|
|
.f4 = true,
|
|
.f5 = @as(f32, @bitCast(@as(u32, 0x00e44046))),
|
|
}, s);
|
|
try std.testing.expectEqual(K{
|
|
.f0 = 0x12,
|
|
.f1 = s,
|
|
.f2 = 0x3412,
|
|
.f3 = .{0x12},
|
|
.f4 = false,
|
|
.f5 = @as(f32, @bitCast(@as(u32, 0x0028d445))),
|
|
}, k);
|
|
}
|
|
|
|
pub const tokenize = @compileError("deprecated; use tokenizeAny, tokenizeSequence, or tokenizeScalar");
|
|
|
|
/// Returns an iterator that iterates over the slices of `buffer` that are not
|
|
/// any of the items in `delimiters`.
|
|
///
|
|
/// `tokenizeAny(u8, " abc|def || ghi ", " |")` will return slices
|
|
/// for "abc", "def", "ghi", null, in that order.
|
|
///
|
|
/// If `buffer` is empty, the iterator will return null.
|
|
/// If none of `delimiters` exist in buffer,
|
|
/// the iterator will return `buffer`, null, in that order.
|
|
///
|
|
/// See also: `tokenizeSequence`, `tokenizeScalar`,
|
|
/// `splitSequence`,`splitAny`, `splitScalar`,
|
|
/// `splitBackwardsSequence`, `splitBackwardsAny`, and `splitBackwardsScalar`
|
|
pub fn tokenizeAny(comptime T: type, buffer: []const T, delimiters: []const T) TokenIterator(T, .any) {
|
|
return .{
|
|
.index = 0,
|
|
.buffer = buffer,
|
|
.delimiter = delimiters,
|
|
};
|
|
}
|
|
|
|
/// Returns an iterator that iterates over the slices of `buffer` that are not
|
|
/// the sequence in `delimiter`.
|
|
///
|
|
/// `tokenizeSequence(u8, "<>abc><def<><>ghi", "<>")` will return slices
|
|
/// for "abc><def", "ghi", null, in that order.
|
|
///
|
|
/// If `buffer` is empty, the iterator will return null.
|
|
/// If `delimiter` does not exist in buffer,
|
|
/// the iterator will return `buffer`, null, in that order.
|
|
/// The delimiter length must not be zero.
|
|
///
|
|
/// See also: `tokenizeAny`, `tokenizeScalar`,
|
|
/// `splitSequence`,`splitAny`, and `splitScalar`
|
|
/// `splitBackwardsSequence`, `splitBackwardsAny`, and `splitBackwardsScalar`
|
|
pub fn tokenizeSequence(comptime T: type, buffer: []const T, delimiter: []const T) TokenIterator(T, .sequence) {
|
|
assert(delimiter.len != 0);
|
|
return .{
|
|
.index = 0,
|
|
.buffer = buffer,
|
|
.delimiter = delimiter,
|
|
};
|
|
}
|
|
|
|
/// Returns an iterator that iterates over the slices of `buffer` that are not
|
|
/// `delimiter`.
|
|
///
|
|
/// `tokenizeScalar(u8, " abc def ghi ", ' ')` will return slices
|
|
/// for "abc", "def", "ghi", null, in that order.
|
|
///
|
|
/// If `buffer` is empty, the iterator will return null.
|
|
/// If `delimiter` does not exist in buffer,
|
|
/// the iterator will return `buffer`, null, in that order.
|
|
///
|
|
/// See also: `tokenizeAny`, `tokenizeSequence`,
|
|
/// `splitSequence`,`splitAny`, and `splitScalar`
|
|
/// `splitBackwardsSequence`, `splitBackwardsAny`, and `splitBackwardsScalar`
|
|
pub fn tokenizeScalar(comptime T: type, buffer: []const T, delimiter: T) TokenIterator(T, .scalar) {
|
|
return .{
|
|
.index = 0,
|
|
.buffer = buffer,
|
|
.delimiter = delimiter,
|
|
};
|
|
}
|
|
|
|
test tokenizeScalar {
|
|
var it = tokenizeScalar(u8, " abc def ghi ", ' ');
|
|
try testing.expect(eql(u8, it.next().?, "abc"));
|
|
try testing.expect(eql(u8, it.peek().?, "def"));
|
|
try testing.expect(eql(u8, it.next().?, "def"));
|
|
try testing.expect(eql(u8, it.next().?, "ghi"));
|
|
try testing.expect(it.next() == null);
|
|
|
|
it = tokenizeScalar(u8, "..\\bob", '\\');
|
|
try testing.expect(eql(u8, it.next().?, ".."));
|
|
try testing.expect(eql(u8, "..", "..\\bob"[0..it.index]));
|
|
try testing.expect(eql(u8, it.next().?, "bob"));
|
|
try testing.expect(it.next() == null);
|
|
|
|
it = tokenizeScalar(u8, "//a/b", '/');
|
|
try testing.expect(eql(u8, it.next().?, "a"));
|
|
try testing.expect(eql(u8, it.next().?, "b"));
|
|
try testing.expect(eql(u8, "//a/b", "//a/b"[0..it.index]));
|
|
try testing.expect(it.next() == null);
|
|
|
|
it = tokenizeScalar(u8, "|", '|');
|
|
try testing.expect(it.next() == null);
|
|
try testing.expect(it.peek() == null);
|
|
|
|
it = tokenizeScalar(u8, "", '|');
|
|
try testing.expect(it.next() == null);
|
|
try testing.expect(it.peek() == null);
|
|
|
|
it = tokenizeScalar(u8, "hello", ' ');
|
|
try testing.expect(eql(u8, it.next().?, "hello"));
|
|
try testing.expect(it.next() == null);
|
|
|
|
var it16 = tokenizeScalar(
|
|
u16,
|
|
std.unicode.utf8ToUtf16LeStringLiteral("hello"),
|
|
' ',
|
|
);
|
|
try testing.expect(eql(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("hello")));
|
|
try testing.expect(it16.next() == null);
|
|
}
|
|
|
|
test tokenizeAny {
|
|
var it = tokenizeAny(u8, "a|b,c/d e", " /,|");
|
|
try testing.expect(eql(u8, it.next().?, "a"));
|
|
try testing.expect(eql(u8, it.peek().?, "b"));
|
|
try testing.expect(eql(u8, it.next().?, "b"));
|
|
try testing.expect(eql(u8, it.next().?, "c"));
|
|
try testing.expect(eql(u8, it.next().?, "d"));
|
|
try testing.expect(eql(u8, it.next().?, "e"));
|
|
try testing.expect(it.next() == null);
|
|
try testing.expect(it.peek() == null);
|
|
|
|
it = tokenizeAny(u8, "hello", "");
|
|
try testing.expect(eql(u8, it.next().?, "hello"));
|
|
try testing.expect(it.next() == null);
|
|
|
|
var it16 = tokenizeAny(
|
|
u16,
|
|
std.unicode.utf8ToUtf16LeStringLiteral("a|b,c/d e"),
|
|
std.unicode.utf8ToUtf16LeStringLiteral(" /,|"),
|
|
);
|
|
try testing.expect(eql(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("a")));
|
|
try testing.expect(eql(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("b")));
|
|
try testing.expect(eql(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("c")));
|
|
try testing.expect(eql(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("d")));
|
|
try testing.expect(eql(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("e")));
|
|
try testing.expect(it16.next() == null);
|
|
}
|
|
|
|
test tokenizeSequence {
|
|
var it = tokenizeSequence(u8, "a<>b<><>c><>d><", "<>");
|
|
try testing.expectEqualStrings("a", it.next().?);
|
|
try testing.expectEqualStrings("b", it.peek().?);
|
|
try testing.expectEqualStrings("b", it.next().?);
|
|
try testing.expectEqualStrings("c>", it.next().?);
|
|
try testing.expectEqualStrings("d><", it.next().?);
|
|
try testing.expect(it.next() == null);
|
|
try testing.expect(it.peek() == null);
|
|
|
|
var it16 = tokenizeSequence(
|
|
u16,
|
|
std.unicode.utf8ToUtf16LeStringLiteral("a<>b<><>c><>d><"),
|
|
std.unicode.utf8ToUtf16LeStringLiteral("<>"),
|
|
);
|
|
try testing.expect(eql(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("a")));
|
|
try testing.expect(eql(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("b")));
|
|
try testing.expect(eql(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("c>")));
|
|
try testing.expect(eql(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("d><")));
|
|
try testing.expect(it16.next() == null);
|
|
}
|
|
|
|
test "tokenize (reset)" {
|
|
{
|
|
var it = tokenizeAny(u8, " abc def ghi ", " ");
|
|
try testing.expect(eql(u8, it.next().?, "abc"));
|
|
try testing.expect(eql(u8, it.next().?, "def"));
|
|
try testing.expect(eql(u8, it.next().?, "ghi"));
|
|
|
|
it.reset();
|
|
|
|
try testing.expect(eql(u8, it.next().?, "abc"));
|
|
try testing.expect(eql(u8, it.next().?, "def"));
|
|
try testing.expect(eql(u8, it.next().?, "ghi"));
|
|
try testing.expect(it.next() == null);
|
|
}
|
|
{
|
|
var it = tokenizeSequence(u8, "<><>abc<>def<><>ghi<>", "<>");
|
|
try testing.expect(eql(u8, it.next().?, "abc"));
|
|
try testing.expect(eql(u8, it.next().?, "def"));
|
|
try testing.expect(eql(u8, it.next().?, "ghi"));
|
|
|
|
it.reset();
|
|
|
|
try testing.expect(eql(u8, it.next().?, "abc"));
|
|
try testing.expect(eql(u8, it.next().?, "def"));
|
|
try testing.expect(eql(u8, it.next().?, "ghi"));
|
|
try testing.expect(it.next() == null);
|
|
}
|
|
{
|
|
var it = tokenizeScalar(u8, " abc def ghi ", ' ');
|
|
try testing.expect(eql(u8, it.next().?, "abc"));
|
|
try testing.expect(eql(u8, it.next().?, "def"));
|
|
try testing.expect(eql(u8, it.next().?, "ghi"));
|
|
|
|
it.reset();
|
|
|
|
try testing.expect(eql(u8, it.next().?, "abc"));
|
|
try testing.expect(eql(u8, it.next().?, "def"));
|
|
try testing.expect(eql(u8, it.next().?, "ghi"));
|
|
try testing.expect(it.next() == null);
|
|
}
|
|
}
|
|
|
|
pub const split = @compileError("deprecated; use splitSequence, splitAny, or splitScalar");
|
|
|
|
/// Returns an iterator that iterates over the slices of `buffer` that
|
|
/// are separated by the byte sequence in `delimiter`.
|
|
///
|
|
/// `splitSequence(u8, "abc||def||||ghi", "||")` will return slices
|
|
/// for "abc", "def", "", "ghi", null, in that order.
|
|
///
|
|
/// If `delimiter` does not exist in buffer,
|
|
/// the iterator will return `buffer`, null, in that order.
|
|
/// The delimiter length must not be zero.
|
|
///
|
|
/// See also: `splitAny`, `splitScalar`, `splitBackwardsSequence`,
|
|
/// `splitBackwardsAny`,`splitBackwardsScalar`,
|
|
/// `tokenizeAny`, `tokenizeSequence`, and `tokenizeScalar`.
|
|
pub fn splitSequence(comptime T: type, buffer: []const T, delimiter: []const T) SplitIterator(T, .sequence) {
|
|
assert(delimiter.len != 0);
|
|
return .{
|
|
.index = 0,
|
|
.buffer = buffer,
|
|
.delimiter = delimiter,
|
|
};
|
|
}
|
|
|
|
/// Returns an iterator that iterates over the slices of `buffer` that
|
|
/// are separated by any item in `delimiters`.
|
|
///
|
|
/// `splitAny(u8, "abc,def||ghi", "|,")` will return slices
|
|
/// for "abc", "def", "", "ghi", null, in that order.
|
|
///
|
|
/// If none of `delimiters` exist in buffer,
|
|
/// the iterator will return `buffer`, null, in that order.
|
|
///
|
|
/// See also: `splitSequence`, `splitScalar`, `splitBackwardsSequence`,
|
|
/// `splitBackwardsAny`,`splitBackwardsScalar`,
|
|
/// `tokenizeAny`, `tokenizeSequence`, and `tokenizeScalar`.
|
|
pub fn splitAny(comptime T: type, buffer: []const T, delimiters: []const T) SplitIterator(T, .any) {
|
|
return .{
|
|
.index = 0,
|
|
.buffer = buffer,
|
|
.delimiter = delimiters,
|
|
};
|
|
}
|
|
|
|
/// Returns an iterator that iterates over the slices of `buffer` that
|
|
/// are separated by `delimiter`.
|
|
///
|
|
/// `splitScalar(u8, "abc|def||ghi", '|')` will return slices
|
|
/// for "abc", "def", "", "ghi", null, in that order.
|
|
///
|
|
/// If `delimiter` does not exist in buffer,
|
|
/// the iterator will return `buffer`, null, in that order.
|
|
///
|
|
/// See also: `splitSequence`, `splitAny`, `splitBackwardsSequence`,
|
|
/// `splitBackwardsAny`,`splitBackwardsScalar`,
|
|
/// `tokenizeAny`, `tokenizeSequence`, and `tokenizeScalar`.
|
|
pub fn splitScalar(comptime T: type, buffer: []const T, delimiter: T) SplitIterator(T, .scalar) {
|
|
return .{
|
|
.index = 0,
|
|
.buffer = buffer,
|
|
.delimiter = delimiter,
|
|
};
|
|
}
|
|
|
|
test splitScalar {
|
|
var it = splitScalar(u8, "abc|def||ghi", '|');
|
|
try testing.expectEqualSlices(u8, it.rest(), "abc|def||ghi");
|
|
try testing.expectEqualSlices(u8, it.first(), "abc");
|
|
|
|
try testing.expectEqualSlices(u8, it.rest(), "def||ghi");
|
|
try testing.expectEqualSlices(u8, it.peek().?, "def");
|
|
try testing.expectEqualSlices(u8, it.next().?, "def");
|
|
|
|
try testing.expectEqualSlices(u8, it.rest(), "|ghi");
|
|
try testing.expectEqualSlices(u8, it.next().?, "");
|
|
|
|
try testing.expectEqualSlices(u8, it.rest(), "ghi");
|
|
try testing.expectEqualSlices(u8, it.peek().?, "ghi");
|
|
try testing.expectEqualSlices(u8, it.next().?, "ghi");
|
|
|
|
try testing.expectEqualSlices(u8, it.rest(), "");
|
|
try testing.expect(it.peek() == null);
|
|
try testing.expect(it.next() == null);
|
|
|
|
it = splitScalar(u8, "", '|');
|
|
try testing.expectEqualSlices(u8, it.first(), "");
|
|
try testing.expect(it.next() == null);
|
|
|
|
it = splitScalar(u8, "|", '|');
|
|
try testing.expectEqualSlices(u8, it.first(), "");
|
|
try testing.expectEqualSlices(u8, it.next().?, "");
|
|
try testing.expect(it.peek() == null);
|
|
try testing.expect(it.next() == null);
|
|
|
|
it = splitScalar(u8, "hello", ' ');
|
|
try testing.expectEqualSlices(u8, it.first(), "hello");
|
|
try testing.expect(it.next() == null);
|
|
|
|
var it16 = splitScalar(
|
|
u16,
|
|
std.unicode.utf8ToUtf16LeStringLiteral("hello"),
|
|
' ',
|
|
);
|
|
try testing.expectEqualSlices(u16, it16.first(), std.unicode.utf8ToUtf16LeStringLiteral("hello"));
|
|
try testing.expect(it16.next() == null);
|
|
}
|
|
|
|
test splitSequence {
|
|
var it = splitSequence(u8, "a, b ,, c, d, e", ", ");
|
|
try testing.expectEqualSlices(u8, it.first(), "a");
|
|
try testing.expectEqualSlices(u8, it.rest(), "b ,, c, d, e");
|
|
try testing.expectEqualSlices(u8, it.next().?, "b ,");
|
|
try testing.expectEqualSlices(u8, it.next().?, "c");
|
|
try testing.expectEqualSlices(u8, it.next().?, "d");
|
|
try testing.expectEqualSlices(u8, it.next().?, "e");
|
|
try testing.expect(it.next() == null);
|
|
|
|
var it16 = splitSequence(
|
|
u16,
|
|
std.unicode.utf8ToUtf16LeStringLiteral("a, b ,, c, d, e"),
|
|
std.unicode.utf8ToUtf16LeStringLiteral(", "),
|
|
);
|
|
try testing.expectEqualSlices(u16, it16.first(), std.unicode.utf8ToUtf16LeStringLiteral("a"));
|
|
try testing.expectEqualSlices(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("b ,"));
|
|
try testing.expectEqualSlices(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("c"));
|
|
try testing.expectEqualSlices(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("d"));
|
|
try testing.expectEqualSlices(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("e"));
|
|
try testing.expect(it16.next() == null);
|
|
}
|
|
|
|
test splitAny {
|
|
var it = splitAny(u8, "a,b, c d e", ", ");
|
|
try testing.expectEqualSlices(u8, it.first(), "a");
|
|
try testing.expectEqualSlices(u8, it.rest(), "b, c d e");
|
|
try testing.expectEqualSlices(u8, it.next().?, "b");
|
|
try testing.expectEqualSlices(u8, it.next().?, "");
|
|
try testing.expectEqualSlices(u8, it.next().?, "c");
|
|
try testing.expectEqualSlices(u8, it.next().?, "d");
|
|
try testing.expectEqualSlices(u8, it.next().?, "e");
|
|
try testing.expect(it.next() == null);
|
|
|
|
it = splitAny(u8, "hello", "");
|
|
try testing.expect(eql(u8, it.next().?, "hello"));
|
|
try testing.expect(it.next() == null);
|
|
|
|
var it16 = splitAny(
|
|
u16,
|
|
std.unicode.utf8ToUtf16LeStringLiteral("a,b, c d e"),
|
|
std.unicode.utf8ToUtf16LeStringLiteral(", "),
|
|
);
|
|
try testing.expectEqualSlices(u16, it16.first(), std.unicode.utf8ToUtf16LeStringLiteral("a"));
|
|
try testing.expectEqualSlices(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("b"));
|
|
try testing.expectEqualSlices(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral(""));
|
|
try testing.expectEqualSlices(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("c"));
|
|
try testing.expectEqualSlices(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("d"));
|
|
try testing.expectEqualSlices(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("e"));
|
|
try testing.expect(it16.next() == null);
|
|
}
|
|
|
|
test "split (reset)" {
|
|
{
|
|
var it = splitSequence(u8, "abc def ghi", " ");
|
|
try testing.expect(eql(u8, it.first(), "abc"));
|
|
try testing.expect(eql(u8, it.next().?, "def"));
|
|
try testing.expect(eql(u8, it.next().?, "ghi"));
|
|
|
|
it.reset();
|
|
|
|
try testing.expect(eql(u8, it.first(), "abc"));
|
|
try testing.expect(eql(u8, it.next().?, "def"));
|
|
try testing.expect(eql(u8, it.next().?, "ghi"));
|
|
try testing.expect(it.next() == null);
|
|
}
|
|
{
|
|
var it = splitAny(u8, "abc def,ghi", " ,");
|
|
try testing.expect(eql(u8, it.first(), "abc"));
|
|
try testing.expect(eql(u8, it.next().?, "def"));
|
|
try testing.expect(eql(u8, it.next().?, "ghi"));
|
|
|
|
it.reset();
|
|
|
|
try testing.expect(eql(u8, it.first(), "abc"));
|
|
try testing.expect(eql(u8, it.next().?, "def"));
|
|
try testing.expect(eql(u8, it.next().?, "ghi"));
|
|
try testing.expect(it.next() == null);
|
|
}
|
|
{
|
|
var it = splitScalar(u8, "abc def ghi", ' ');
|
|
try testing.expect(eql(u8, it.first(), "abc"));
|
|
try testing.expect(eql(u8, it.next().?, "def"));
|
|
try testing.expect(eql(u8, it.next().?, "ghi"));
|
|
|
|
it.reset();
|
|
|
|
try testing.expect(eql(u8, it.first(), "abc"));
|
|
try testing.expect(eql(u8, it.next().?, "def"));
|
|
try testing.expect(eql(u8, it.next().?, "ghi"));
|
|
try testing.expect(it.next() == null);
|
|
}
|
|
}
|
|
|
|
pub const splitBackwards = @compileError("deprecated; use splitBackwardsSequence, splitBackwardsAny, or splitBackwardsScalar");
|
|
|
|
/// Returns an iterator that iterates backwards over the slices of `buffer` that
|
|
/// are separated by the sequence in `delimiter`.
|
|
///
|
|
/// `splitBackwardsSequence(u8, "abc||def||||ghi", "||")` will return slices
|
|
/// for "ghi", "", "def", "abc", null, in that order.
|
|
///
|
|
/// If `delimiter` does not exist in buffer,
|
|
/// the iterator will return `buffer`, null, in that order.
|
|
/// The delimiter length must not be zero.
|
|
///
|
|
/// See also: `splitBackwardsAny`, `splitBackwardsScalar`,
|
|
/// `splitSequence`, `splitAny`,`splitScalar`,
|
|
/// `tokenizeAny`, `tokenizeSequence`, and `tokenizeScalar`.
|
|
pub fn splitBackwardsSequence(comptime T: type, buffer: []const T, delimiter: []const T) SplitBackwardsIterator(T, .sequence) {
|
|
assert(delimiter.len != 0);
|
|
return .{
|
|
.index = buffer.len,
|
|
.buffer = buffer,
|
|
.delimiter = delimiter,
|
|
};
|
|
}
|
|
|
|
/// Returns an iterator that iterates backwards over the slices of `buffer` that
|
|
/// are separated by any item in `delimiters`.
|
|
///
|
|
/// `splitBackwardsAny(u8, "abc,def||ghi", "|,")` will return slices
|
|
/// for "ghi", "", "def", "abc", null, in that order.
|
|
///
|
|
/// If none of `delimiters` exist in buffer,
|
|
/// the iterator will return `buffer`, null, in that order.
|
|
///
|
|
/// See also: `splitBackwardsSequence`, `splitBackwardsScalar`,
|
|
/// `splitSequence`, `splitAny`,`splitScalar`,
|
|
/// `tokenizeAny`, `tokenizeSequence`, and `tokenizeScalar`.
|
|
pub fn splitBackwardsAny(comptime T: type, buffer: []const T, delimiters: []const T) SplitBackwardsIterator(T, .any) {
|
|
return .{
|
|
.index = buffer.len,
|
|
.buffer = buffer,
|
|
.delimiter = delimiters,
|
|
};
|
|
}
|
|
|
|
/// Returns an iterator that iterates backwards over the slices of `buffer` that
|
|
/// are separated by `delimiter`.
|
|
///
|
|
/// `splitBackwardsScalar(u8, "abc|def||ghi", '|')` will return slices
|
|
/// for "ghi", "", "def", "abc", null, in that order.
|
|
///
|
|
/// If `delimiter` does not exist in buffer,
|
|
/// the iterator will return `buffer`, null, in that order.
|
|
///
|
|
/// See also: `splitBackwardsSequence`, `splitBackwardsAny`,
|
|
/// `splitSequence`, `splitAny`,`splitScalar`,
|
|
/// `tokenizeAny`, `tokenizeSequence`, and `tokenizeScalar`.
|
|
pub fn splitBackwardsScalar(comptime T: type, buffer: []const T, delimiter: T) SplitBackwardsIterator(T, .scalar) {
|
|
return .{
|
|
.index = buffer.len,
|
|
.buffer = buffer,
|
|
.delimiter = delimiter,
|
|
};
|
|
}
|
|
|
|
test splitBackwardsScalar {
|
|
var it = splitBackwardsScalar(u8, "abc|def||ghi", '|');
|
|
try testing.expectEqualSlices(u8, it.rest(), "abc|def||ghi");
|
|
try testing.expectEqualSlices(u8, it.first(), "ghi");
|
|
|
|
try testing.expectEqualSlices(u8, it.rest(), "abc|def|");
|
|
try testing.expectEqualSlices(u8, it.next().?, "");
|
|
|
|
try testing.expectEqualSlices(u8, it.rest(), "abc|def");
|
|
try testing.expectEqualSlices(u8, it.next().?, "def");
|
|
|
|
try testing.expectEqualSlices(u8, it.rest(), "abc");
|
|
try testing.expectEqualSlices(u8, it.next().?, "abc");
|
|
|
|
try testing.expectEqualSlices(u8, it.rest(), "");
|
|
try testing.expect(it.next() == null);
|
|
|
|
it = splitBackwardsScalar(u8, "", '|');
|
|
try testing.expectEqualSlices(u8, it.first(), "");
|
|
try testing.expect(it.next() == null);
|
|
|
|
it = splitBackwardsScalar(u8, "|", '|');
|
|
try testing.expectEqualSlices(u8, it.first(), "");
|
|
try testing.expectEqualSlices(u8, it.next().?, "");
|
|
try testing.expect(it.next() == null);
|
|
|
|
it = splitBackwardsScalar(u8, "hello", ' ');
|
|
try testing.expectEqualSlices(u8, it.first(), "hello");
|
|
try testing.expect(it.next() == null);
|
|
|
|
var it16 = splitBackwardsScalar(
|
|
u16,
|
|
std.unicode.utf8ToUtf16LeStringLiteral("hello"),
|
|
' ',
|
|
);
|
|
try testing.expectEqualSlices(u16, it16.first(), std.unicode.utf8ToUtf16LeStringLiteral("hello"));
|
|
try testing.expect(it16.next() == null);
|
|
}
|
|
|
|
test splitBackwardsSequence {
|
|
var it = splitBackwardsSequence(u8, "a, b ,, c, d, e", ", ");
|
|
try testing.expectEqualSlices(u8, it.rest(), "a, b ,, c, d, e");
|
|
try testing.expectEqualSlices(u8, it.first(), "e");
|
|
|
|
try testing.expectEqualSlices(u8, it.rest(), "a, b ,, c, d");
|
|
try testing.expectEqualSlices(u8, it.next().?, "d");
|
|
|
|
try testing.expectEqualSlices(u8, it.rest(), "a, b ,, c");
|
|
try testing.expectEqualSlices(u8, it.next().?, "c");
|
|
|
|
try testing.expectEqualSlices(u8, it.rest(), "a, b ,");
|
|
try testing.expectEqualSlices(u8, it.next().?, "b ,");
|
|
|
|
try testing.expectEqualSlices(u8, it.rest(), "a");
|
|
try testing.expectEqualSlices(u8, it.next().?, "a");
|
|
|
|
try testing.expectEqualSlices(u8, it.rest(), "");
|
|
try testing.expect(it.next() == null);
|
|
|
|
var it16 = splitBackwardsSequence(
|
|
u16,
|
|
std.unicode.utf8ToUtf16LeStringLiteral("a, b ,, c, d, e"),
|
|
std.unicode.utf8ToUtf16LeStringLiteral(", "),
|
|
);
|
|
try testing.expectEqualSlices(u16, it16.first(), std.unicode.utf8ToUtf16LeStringLiteral("e"));
|
|
try testing.expectEqualSlices(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("d"));
|
|
try testing.expectEqualSlices(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("c"));
|
|
try testing.expectEqualSlices(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("b ,"));
|
|
try testing.expectEqualSlices(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("a"));
|
|
try testing.expect(it16.next() == null);
|
|
}
|
|
|
|
test splitBackwardsAny {
|
|
var it = splitBackwardsAny(u8, "a,b, c d e", ", ");
|
|
try testing.expectEqualSlices(u8, it.rest(), "a,b, c d e");
|
|
try testing.expectEqualSlices(u8, it.first(), "e");
|
|
|
|
try testing.expectEqualSlices(u8, it.rest(), "a,b, c d");
|
|
try testing.expectEqualSlices(u8, it.next().?, "d");
|
|
|
|
try testing.expectEqualSlices(u8, it.rest(), "a,b, c");
|
|
try testing.expectEqualSlices(u8, it.next().?, "c");
|
|
|
|
try testing.expectEqualSlices(u8, it.rest(), "a,b,");
|
|
try testing.expectEqualSlices(u8, it.next().?, "");
|
|
|
|
try testing.expectEqualSlices(u8, it.rest(), "a,b");
|
|
try testing.expectEqualSlices(u8, it.next().?, "b");
|
|
|
|
try testing.expectEqualSlices(u8, it.rest(), "a");
|
|
try testing.expectEqualSlices(u8, it.next().?, "a");
|
|
|
|
try testing.expectEqualSlices(u8, it.rest(), "");
|
|
try testing.expect(it.next() == null);
|
|
|
|
var it16 = splitBackwardsAny(
|
|
u16,
|
|
std.unicode.utf8ToUtf16LeStringLiteral("a,b, c d e"),
|
|
std.unicode.utf8ToUtf16LeStringLiteral(", "),
|
|
);
|
|
try testing.expectEqualSlices(u16, it16.first(), std.unicode.utf8ToUtf16LeStringLiteral("e"));
|
|
try testing.expectEqualSlices(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("d"));
|
|
try testing.expectEqualSlices(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("c"));
|
|
try testing.expectEqualSlices(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral(""));
|
|
try testing.expectEqualSlices(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("b"));
|
|
try testing.expectEqualSlices(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("a"));
|
|
try testing.expect(it16.next() == null);
|
|
}
|
|
|
|
test "splitBackwards (reset)" {
|
|
{
|
|
var it = splitBackwardsSequence(u8, "abc def ghi", " ");
|
|
try testing.expect(eql(u8, it.first(), "ghi"));
|
|
try testing.expect(eql(u8, it.next().?, "def"));
|
|
try testing.expect(eql(u8, it.next().?, "abc"));
|
|
|
|
it.reset();
|
|
|
|
try testing.expect(eql(u8, it.first(), "ghi"));
|
|
try testing.expect(eql(u8, it.next().?, "def"));
|
|
try testing.expect(eql(u8, it.next().?, "abc"));
|
|
try testing.expect(it.next() == null);
|
|
}
|
|
{
|
|
var it = splitBackwardsAny(u8, "abc def,ghi", " ,");
|
|
try testing.expect(eql(u8, it.first(), "ghi"));
|
|
try testing.expect(eql(u8, it.next().?, "def"));
|
|
try testing.expect(eql(u8, it.next().?, "abc"));
|
|
|
|
it.reset();
|
|
|
|
try testing.expect(eql(u8, it.first(), "ghi"));
|
|
try testing.expect(eql(u8, it.next().?, "def"));
|
|
try testing.expect(eql(u8, it.next().?, "abc"));
|
|
try testing.expect(it.next() == null);
|
|
}
|
|
{
|
|
var it = splitBackwardsScalar(u8, "abc def ghi", ' ');
|
|
try testing.expect(eql(u8, it.first(), "ghi"));
|
|
try testing.expect(eql(u8, it.next().?, "def"));
|
|
try testing.expect(eql(u8, it.next().?, "abc"));
|
|
|
|
it.reset();
|
|
|
|
try testing.expect(eql(u8, it.first(), "ghi"));
|
|
try testing.expect(eql(u8, it.next().?, "def"));
|
|
try testing.expect(eql(u8, it.next().?, "abc"));
|
|
try testing.expect(it.next() == null);
|
|
}
|
|
}
|
|
|
|
/// Returns an iterator with a sliding window of slices for `buffer`.
|
|
/// The sliding window has length `size` and on every iteration moves
|
|
/// forward by `advance`.
|
|
///
|
|
/// Extract data for moving average with:
|
|
/// `window(u8, "abcdefg", 3, 1)` will return slices
|
|
/// "abc", "bcd", "cde", "def", "efg", null, in that order.
|
|
///
|
|
/// Chunk or split every N items with:
|
|
/// `window(u8, "abcdefg", 3, 3)` will return slices
|
|
/// "abc", "def", "g", null, in that order.
|
|
///
|
|
/// Pick every even index with:
|
|
/// `window(u8, "abcdefg", 1, 2)` will return slices
|
|
/// "a", "c", "e", "g" null, in that order.
|
|
///
|
|
/// The `size` and `advance` must be not be zero.
|
|
pub fn window(comptime T: type, buffer: []const T, size: usize, advance: usize) WindowIterator(T) {
|
|
assert(size != 0);
|
|
assert(advance != 0);
|
|
return .{
|
|
.index = 0,
|
|
.buffer = buffer,
|
|
.size = size,
|
|
.advance = advance,
|
|
};
|
|
}
|
|
|
|
test window {
|
|
{
|
|
// moving average size 3
|
|
var it = window(u8, "abcdefg", 3, 1);
|
|
try testing.expectEqualSlices(u8, it.next().?, "abc");
|
|
try testing.expectEqualSlices(u8, it.next().?, "bcd");
|
|
try testing.expectEqualSlices(u8, it.next().?, "cde");
|
|
try testing.expectEqualSlices(u8, it.next().?, "def");
|
|
try testing.expectEqualSlices(u8, it.next().?, "efg");
|
|
try testing.expectEqual(it.next(), null);
|
|
|
|
// multibyte
|
|
var it16 = window(u16, std.unicode.utf8ToUtf16LeStringLiteral("abcdefg"), 3, 1);
|
|
try testing.expectEqualSlices(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("abc"));
|
|
try testing.expectEqualSlices(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("bcd"));
|
|
try testing.expectEqualSlices(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("cde"));
|
|
try testing.expectEqualSlices(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("def"));
|
|
try testing.expectEqualSlices(u16, it16.next().?, std.unicode.utf8ToUtf16LeStringLiteral("efg"));
|
|
try testing.expectEqual(it16.next(), null);
|
|
}
|
|
|
|
{
|
|
// chunk/split every 3
|
|
var it = window(u8, "abcdefg", 3, 3);
|
|
try testing.expectEqualSlices(u8, it.next().?, "abc");
|
|
try testing.expectEqualSlices(u8, it.next().?, "def");
|
|
try testing.expectEqualSlices(u8, it.next().?, "g");
|
|
try testing.expectEqual(it.next(), null);
|
|
}
|
|
|
|
{
|
|
// pick even
|
|
var it = window(u8, "abcdefg", 1, 2);
|
|
try testing.expectEqualSlices(u8, it.next().?, "a");
|
|
try testing.expectEqualSlices(u8, it.next().?, "c");
|
|
try testing.expectEqualSlices(u8, it.next().?, "e");
|
|
try testing.expectEqualSlices(u8, it.next().?, "g");
|
|
try testing.expectEqual(it.next(), null);
|
|
}
|
|
|
|
{
|
|
// empty
|
|
var it = window(u8, "", 1, 1);
|
|
try testing.expectEqualSlices(u8, it.next().?, "");
|
|
try testing.expectEqual(it.next(), null);
|
|
|
|
it = window(u8, "", 10, 1);
|
|
try testing.expectEqualSlices(u8, it.next().?, "");
|
|
try testing.expectEqual(it.next(), null);
|
|
|
|
it = window(u8, "", 1, 10);
|
|
try testing.expectEqualSlices(u8, it.next().?, "");
|
|
try testing.expectEqual(it.next(), null);
|
|
|
|
it = window(u8, "", 10, 10);
|
|
try testing.expectEqualSlices(u8, it.next().?, "");
|
|
try testing.expectEqual(it.next(), null);
|
|
}
|
|
|
|
{
|
|
// first
|
|
var it = window(u8, "abcdefg", 3, 3);
|
|
try testing.expectEqualSlices(u8, it.first(), "abc");
|
|
it.reset();
|
|
try testing.expectEqualSlices(u8, it.next().?, "abc");
|
|
}
|
|
|
|
{
|
|
// reset
|
|
var it = window(u8, "abcdefg", 3, 3);
|
|
try testing.expectEqualSlices(u8, it.next().?, "abc");
|
|
try testing.expectEqualSlices(u8, it.next().?, "def");
|
|
try testing.expectEqualSlices(u8, it.next().?, "g");
|
|
try testing.expectEqual(it.next(), null);
|
|
|
|
it.reset();
|
|
try testing.expectEqualSlices(u8, it.next().?, "abc");
|
|
try testing.expectEqualSlices(u8, it.next().?, "def");
|
|
try testing.expectEqualSlices(u8, it.next().?, "g");
|
|
try testing.expectEqual(it.next(), null);
|
|
}
|
|
}
|
|
|
|
pub fn WindowIterator(comptime T: type) type {
|
|
return struct {
|
|
buffer: []const T,
|
|
index: ?usize,
|
|
size: usize,
|
|
advance: usize,
|
|
|
|
const Self = @This();
|
|
|
|
/// Returns a slice of the first window. This never fails.
|
|
/// Call this only to get the first window and then use `next` to get
|
|
/// all subsequent windows.
|
|
pub fn first(self: *Self) []const T {
|
|
assert(self.index.? == 0);
|
|
return self.next().?;
|
|
}
|
|
|
|
/// Returns a slice of the next window, or null if window is at end.
|
|
pub fn next(self: *Self) ?[]const T {
|
|
const start = self.index orelse return null;
|
|
const next_index = start + self.advance;
|
|
const end = if (start + self.size < self.buffer.len and next_index < self.buffer.len) blk: {
|
|
self.index = next_index;
|
|
break :blk start + self.size;
|
|
} else blk: {
|
|
self.index = null;
|
|
break :blk self.buffer.len;
|
|
};
|
|
|
|
return self.buffer[start..end];
|
|
}
|
|
|
|
/// Resets the iterator to the initial window.
|
|
pub fn reset(self: *Self) void {
|
|
self.index = 0;
|
|
}
|
|
};
|
|
}
|
|
|
|
pub fn startsWith(comptime T: type, haystack: []const T, needle: []const T) bool {
|
|
return if (needle.len > haystack.len) false else eql(T, haystack[0..needle.len], needle);
|
|
}
|
|
|
|
test startsWith {
|
|
try testing.expect(startsWith(u8, "Bob", "Bo"));
|
|
try testing.expect(!startsWith(u8, "Needle in haystack", "haystack"));
|
|
}
|
|
|
|
pub fn endsWith(comptime T: type, haystack: []const T, needle: []const T) bool {
|
|
return if (needle.len > haystack.len) false else eql(T, haystack[haystack.len - needle.len ..], needle);
|
|
}
|
|
|
|
test endsWith {
|
|
try testing.expect(endsWith(u8, "Needle in haystack", "haystack"));
|
|
try testing.expect(!endsWith(u8, "Bob", "Bo"));
|
|
}
|
|
|
|
pub const DelimiterType = enum { sequence, any, scalar };
|
|
|
|
pub fn TokenIterator(comptime T: type, comptime delimiter_type: DelimiterType) type {
|
|
return struct {
|
|
buffer: []const T,
|
|
delimiter: switch (delimiter_type) {
|
|
.sequence, .any => []const T,
|
|
.scalar => T,
|
|
},
|
|
index: usize,
|
|
|
|
const Self = @This();
|
|
|
|
/// Returns a slice of the current token, or null if tokenization is
|
|
/// complete, and advances to the next token.
|
|
pub fn next(self: *Self) ?[]const T {
|
|
const result = self.peek() orelse return null;
|
|
self.index += result.len;
|
|
return result;
|
|
}
|
|
|
|
/// Returns a slice of the current token, or null if tokenization is
|
|
/// complete. Does not advance to the next token.
|
|
pub fn peek(self: *Self) ?[]const T {
|
|
// move to beginning of token
|
|
while (self.index < self.buffer.len and self.isDelimiter(self.index)) : (self.index += switch (delimiter_type) {
|
|
.sequence => self.delimiter.len,
|
|
.any, .scalar => 1,
|
|
}) {}
|
|
const start = self.index;
|
|
if (start == self.buffer.len) {
|
|
return null;
|
|
}
|
|
|
|
// move to end of token
|
|
var end = start;
|
|
while (end < self.buffer.len and !self.isDelimiter(end)) : (end += 1) {}
|
|
|
|
return self.buffer[start..end];
|
|
}
|
|
|
|
/// Returns a slice of the remaining bytes. Does not affect iterator state.
|
|
pub fn rest(self: Self) []const T {
|
|
// move to beginning of token
|
|
var index: usize = self.index;
|
|
while (index < self.buffer.len and self.isDelimiter(index)) : (index += switch (delimiter_type) {
|
|
.sequence => self.delimiter.len,
|
|
.any, .scalar => 1,
|
|
}) {}
|
|
return self.buffer[index..];
|
|
}
|
|
|
|
/// Resets the iterator to the initial token.
|
|
pub fn reset(self: *Self) void {
|
|
self.index = 0;
|
|
}
|
|
|
|
fn isDelimiter(self: Self, index: usize) bool {
|
|
switch (delimiter_type) {
|
|
.sequence => return startsWith(T, self.buffer[index..], self.delimiter),
|
|
.any => {
|
|
const item = self.buffer[index];
|
|
for (self.delimiter) |delimiter_item| {
|
|
if (item == delimiter_item) {
|
|
return true;
|
|
}
|
|
}
|
|
return false;
|
|
},
|
|
.scalar => return self.buffer[index] == self.delimiter,
|
|
}
|
|
}
|
|
};
|
|
}
|
|
|
|
pub fn SplitIterator(comptime T: type, comptime delimiter_type: DelimiterType) type {
|
|
return struct {
|
|
buffer: []const T,
|
|
index: ?usize,
|
|
delimiter: switch (delimiter_type) {
|
|
.sequence, .any => []const T,
|
|
.scalar => T,
|
|
},
|
|
|
|
const Self = @This();
|
|
|
|
/// Returns a slice of the first field. This never fails.
|
|
/// Call this only to get the first field and then use `next` to get all subsequent fields.
|
|
pub fn first(self: *Self) []const T {
|
|
assert(self.index.? == 0);
|
|
return self.next().?;
|
|
}
|
|
|
|
/// Returns a slice of the next field, or null if splitting is complete.
|
|
pub fn next(self: *Self) ?[]const T {
|
|
const start = self.index orelse return null;
|
|
const end = if (switch (delimiter_type) {
|
|
.sequence => indexOfPos(T, self.buffer, start, self.delimiter),
|
|
.any => indexOfAnyPos(T, self.buffer, start, self.delimiter),
|
|
.scalar => indexOfScalarPos(T, self.buffer, start, self.delimiter),
|
|
}) |delim_start| blk: {
|
|
self.index = delim_start + switch (delimiter_type) {
|
|
.sequence => self.delimiter.len,
|
|
.any, .scalar => 1,
|
|
};
|
|
break :blk delim_start;
|
|
} else blk: {
|
|
self.index = null;
|
|
break :blk self.buffer.len;
|
|
};
|
|
return self.buffer[start..end];
|
|
}
|
|
|
|
/// Returns a slice of the next field, or null if splitting is complete.
|
|
/// This method does not alter self.index.
|
|
pub fn peek(self: *Self) ?[]const T {
|
|
const start = self.index orelse return null;
|
|
const end = if (switch (delimiter_type) {
|
|
.sequence => indexOfPos(T, self.buffer, start, self.delimiter),
|
|
.any => indexOfAnyPos(T, self.buffer, start, self.delimiter),
|
|
.scalar => indexOfScalarPos(T, self.buffer, start, self.delimiter),
|
|
}) |delim_start| delim_start else self.buffer.len;
|
|
return self.buffer[start..end];
|
|
}
|
|
|
|
/// Returns a slice of the remaining bytes. Does not affect iterator state.
|
|
pub fn rest(self: Self) []const T {
|
|
const end = self.buffer.len;
|
|
const start = self.index orelse end;
|
|
return self.buffer[start..end];
|
|
}
|
|
|
|
/// Resets the iterator to the initial slice.
|
|
pub fn reset(self: *Self) void {
|
|
self.index = 0;
|
|
}
|
|
};
|
|
}
|
|
|
|
pub fn SplitBackwardsIterator(comptime T: type, comptime delimiter_type: DelimiterType) type {
|
|
return struct {
|
|
buffer: []const T,
|
|
index: ?usize,
|
|
delimiter: switch (delimiter_type) {
|
|
.sequence, .any => []const T,
|
|
.scalar => T,
|
|
},
|
|
|
|
const Self = @This();
|
|
|
|
/// Returns a slice of the first field. This never fails.
|
|
/// Call this only to get the first field and then use `next` to get all subsequent fields.
|
|
pub fn first(self: *Self) []const T {
|
|
assert(self.index.? == self.buffer.len);
|
|
return self.next().?;
|
|
}
|
|
|
|
/// Returns a slice of the next field, or null if splitting is complete.
|
|
pub fn next(self: *Self) ?[]const T {
|
|
const end = self.index orelse return null;
|
|
const start = if (switch (delimiter_type) {
|
|
.sequence => lastIndexOf(T, self.buffer[0..end], self.delimiter),
|
|
.any => lastIndexOfAny(T, self.buffer[0..end], self.delimiter),
|
|
.scalar => lastIndexOfScalar(T, self.buffer[0..end], self.delimiter),
|
|
}) |delim_start| blk: {
|
|
self.index = delim_start;
|
|
break :blk delim_start + switch (delimiter_type) {
|
|
.sequence => self.delimiter.len,
|
|
.any, .scalar => 1,
|
|
};
|
|
} else blk: {
|
|
self.index = null;
|
|
break :blk 0;
|
|
};
|
|
return self.buffer[start..end];
|
|
}
|
|
|
|
/// Returns a slice of the remaining bytes. Does not affect iterator state.
|
|
pub fn rest(self: Self) []const T {
|
|
const end = self.index orelse 0;
|
|
return self.buffer[0..end];
|
|
}
|
|
|
|
/// Resets the iterator to the initial slice.
|
|
pub fn reset(self: *Self) void {
|
|
self.index = self.buffer.len;
|
|
}
|
|
};
|
|
}
|
|
|
|
/// Naively combines a series of slices with a separator.
|
|
/// Allocates memory for the result, which must be freed by the caller.
|
|
pub fn join(allocator: Allocator, separator: []const u8, slices: []const []const u8) Allocator.Error![]u8 {
|
|
return joinMaybeZ(allocator, separator, slices, false);
|
|
}
|
|
|
|
/// Naively combines a series of slices with a separator and null terminator.
|
|
/// Allocates memory for the result, which must be freed by the caller.
|
|
pub fn joinZ(allocator: Allocator, separator: []const u8, slices: []const []const u8) Allocator.Error![:0]u8 {
|
|
const out = try joinMaybeZ(allocator, separator, slices, true);
|
|
return out[0 .. out.len - 1 :0];
|
|
}
|
|
|
|
fn joinMaybeZ(allocator: Allocator, separator: []const u8, slices: []const []const u8, zero: bool) Allocator.Error![]u8 {
|
|
if (slices.len == 0) return if (zero) try allocator.dupe(u8, &[1]u8{0}) else &[0]u8{};
|
|
|
|
const total_len = blk: {
|
|
var sum: usize = separator.len * (slices.len - 1);
|
|
for (slices) |slice| sum += slice.len;
|
|
if (zero) sum += 1;
|
|
break :blk sum;
|
|
};
|
|
|
|
const buf = try allocator.alloc(u8, total_len);
|
|
errdefer allocator.free(buf);
|
|
|
|
@memcpy(buf[0..slices[0].len], slices[0]);
|
|
var buf_index: usize = slices[0].len;
|
|
for (slices[1..]) |slice| {
|
|
@memcpy(buf[buf_index .. buf_index + separator.len], separator);
|
|
buf_index += separator.len;
|
|
@memcpy(buf[buf_index .. buf_index + slice.len], slice);
|
|
buf_index += slice.len;
|
|
}
|
|
|
|
if (zero) buf[buf.len - 1] = 0;
|
|
|
|
// No need for shrink since buf is exactly the correct size.
|
|
return buf;
|
|
}
|
|
|
|
test join {
|
|
{
|
|
const str = try join(testing.allocator, ",", &[_][]const u8{});
|
|
defer testing.allocator.free(str);
|
|
try testing.expect(eql(u8, str, ""));
|
|
}
|
|
{
|
|
const str = try join(testing.allocator, ",", &[_][]const u8{ "a", "b", "c" });
|
|
defer testing.allocator.free(str);
|
|
try testing.expect(eql(u8, str, "a,b,c"));
|
|
}
|
|
{
|
|
const str = try join(testing.allocator, ",", &[_][]const u8{"a"});
|
|
defer testing.allocator.free(str);
|
|
try testing.expect(eql(u8, str, "a"));
|
|
}
|
|
{
|
|
const str = try join(testing.allocator, ",", &[_][]const u8{ "a", "", "b", "", "c" });
|
|
defer testing.allocator.free(str);
|
|
try testing.expect(eql(u8, str, "a,,b,,c"));
|
|
}
|
|
}
|
|
|
|
test joinZ {
|
|
{
|
|
const str = try joinZ(testing.allocator, ",", &[_][]const u8{});
|
|
defer testing.allocator.free(str);
|
|
try testing.expect(eql(u8, str, ""));
|
|
try testing.expectEqual(str[str.len], 0);
|
|
}
|
|
{
|
|
const str = try joinZ(testing.allocator, ",", &[_][]const u8{ "a", "b", "c" });
|
|
defer testing.allocator.free(str);
|
|
try testing.expect(eql(u8, str, "a,b,c"));
|
|
try testing.expectEqual(str[str.len], 0);
|
|
}
|
|
{
|
|
const str = try joinZ(testing.allocator, ",", &[_][]const u8{"a"});
|
|
defer testing.allocator.free(str);
|
|
try testing.expect(eql(u8, str, "a"));
|
|
try testing.expectEqual(str[str.len], 0);
|
|
}
|
|
{
|
|
const str = try joinZ(testing.allocator, ",", &[_][]const u8{ "a", "", "b", "", "c" });
|
|
defer testing.allocator.free(str);
|
|
try testing.expect(eql(u8, str, "a,,b,,c"));
|
|
try testing.expectEqual(str[str.len], 0);
|
|
}
|
|
}
|
|
|
|
/// Copies each T from slices into a new slice that exactly holds all the elements.
|
|
pub fn concat(allocator: Allocator, comptime T: type, slices: []const []const T) Allocator.Error![]T {
|
|
return concatMaybeSentinel(allocator, T, slices, null);
|
|
}
|
|
|
|
/// Copies each T from slices into a new slice that exactly holds all the elements.
|
|
pub fn concatWithSentinel(allocator: Allocator, comptime T: type, slices: []const []const T, comptime s: T) Allocator.Error![:s]T {
|
|
const ret = try concatMaybeSentinel(allocator, T, slices, s);
|
|
return ret[0 .. ret.len - 1 :s];
|
|
}
|
|
|
|
/// Copies each T from slices into a new slice that exactly holds all the elements as well as the sentinel.
|
|
pub fn concatMaybeSentinel(allocator: Allocator, comptime T: type, slices: []const []const T, comptime s: ?T) Allocator.Error![]T {
|
|
if (slices.len == 0) return if (s) |sentinel| try allocator.dupe(T, &[1]T{sentinel}) else &[0]T{};
|
|
|
|
const total_len = blk: {
|
|
var sum: usize = 0;
|
|
for (slices) |slice| {
|
|
sum += slice.len;
|
|
}
|
|
|
|
if (s) |_| {
|
|
sum += 1;
|
|
}
|
|
|
|
break :blk sum;
|
|
};
|
|
|
|
const buf = try allocator.alloc(T, total_len);
|
|
errdefer allocator.free(buf);
|
|
|
|
var buf_index: usize = 0;
|
|
for (slices) |slice| {
|
|
@memcpy(buf[buf_index .. buf_index + slice.len], slice);
|
|
buf_index += slice.len;
|
|
}
|
|
|
|
if (s) |sentinel| {
|
|
buf[buf.len - 1] = sentinel;
|
|
}
|
|
|
|
// No need for shrink since buf is exactly the correct size.
|
|
return buf;
|
|
}
|
|
|
|
test concat {
|
|
{
|
|
const str = try concat(testing.allocator, u8, &[_][]const u8{ "abc", "def", "ghi" });
|
|
defer testing.allocator.free(str);
|
|
try testing.expect(eql(u8, str, "abcdefghi"));
|
|
}
|
|
{
|
|
const str = try concat(testing.allocator, u32, &[_][]const u32{
|
|
&[_]u32{ 0, 1 },
|
|
&[_]u32{ 2, 3, 4 },
|
|
&[_]u32{},
|
|
&[_]u32{5},
|
|
});
|
|
defer testing.allocator.free(str);
|
|
try testing.expect(eql(u32, str, &[_]u32{ 0, 1, 2, 3, 4, 5 }));
|
|
}
|
|
{
|
|
const str = try concatWithSentinel(testing.allocator, u8, &[_][]const u8{ "abc", "def", "ghi" }, 0);
|
|
defer testing.allocator.free(str);
|
|
try testing.expectEqualSentinel(u8, 0, str, "abcdefghi");
|
|
}
|
|
{
|
|
const slice = try concatWithSentinel(testing.allocator, u8, &[_][]const u8{}, 0);
|
|
defer testing.allocator.free(slice);
|
|
try testing.expectEqualSentinel(u8, 0, slice, &[_:0]u8{});
|
|
}
|
|
{
|
|
const slice = try concatWithSentinel(testing.allocator, u32, &[_][]const u32{
|
|
&[_]u32{ 0, 1 },
|
|
&[_]u32{ 2, 3, 4 },
|
|
&[_]u32{},
|
|
&[_]u32{5},
|
|
}, 2);
|
|
defer testing.allocator.free(slice);
|
|
try testing.expectEqualSentinel(u32, 2, slice, &[_:2]u32{ 0, 1, 2, 3, 4, 5 });
|
|
}
|
|
}
|
|
|
|
test eql {
|
|
try testing.expect(eql(u8, "abcd", "abcd"));
|
|
try testing.expect(!eql(u8, "abcdef", "abZdef"));
|
|
try testing.expect(!eql(u8, "abcdefg", "abcdef"));
|
|
}
|
|
|
|
fn moreReadIntTests() !void {
|
|
{
|
|
const bytes = [_]u8{
|
|
0x12,
|
|
0x34,
|
|
0x56,
|
|
0x78,
|
|
};
|
|
try testing.expect(readInt(u32, &bytes, .big) == 0x12345678);
|
|
try testing.expect(readInt(u32, &bytes, .big) == 0x12345678);
|
|
try testing.expect(readInt(i32, &bytes, .big) == 0x12345678);
|
|
try testing.expect(readInt(u32, &bytes, .little) == 0x78563412);
|
|
try testing.expect(readInt(u32, &bytes, .little) == 0x78563412);
|
|
try testing.expect(readInt(i32, &bytes, .little) == 0x78563412);
|
|
}
|
|
{
|
|
const buf = [_]u8{
|
|
0x00,
|
|
0x00,
|
|
0x12,
|
|
0x34,
|
|
};
|
|
const answer = readInt(u32, &buf, .big);
|
|
try testing.expect(answer == 0x00001234);
|
|
}
|
|
{
|
|
const buf = [_]u8{
|
|
0x12,
|
|
0x34,
|
|
0x00,
|
|
0x00,
|
|
};
|
|
const answer = readInt(u32, &buf, .little);
|
|
try testing.expect(answer == 0x00003412);
|
|
}
|
|
{
|
|
const bytes = [_]u8{
|
|
0xff,
|
|
0xfe,
|
|
};
|
|
try testing.expect(readInt(u16, &bytes, .big) == 0xfffe);
|
|
try testing.expect(readInt(i16, &bytes, .big) == -0x0002);
|
|
try testing.expect(readInt(u16, &bytes, .little) == 0xfeff);
|
|
try testing.expect(readInt(i16, &bytes, .little) == -0x0101);
|
|
}
|
|
}
|
|
|
|
/// Returns the smallest number in a slice. O(n).
|
|
/// `slice` must not be empty.
|
|
pub fn min(comptime T: type, slice: []const T) T {
|
|
assert(slice.len > 0);
|
|
var best = slice[0];
|
|
for (slice[1..]) |item| {
|
|
best = @min(best, item);
|
|
}
|
|
return best;
|
|
}
|
|
|
|
test min {
|
|
try testing.expectEqual(min(u8, "abcdefg"), 'a');
|
|
try testing.expectEqual(min(u8, "bcdefga"), 'a');
|
|
try testing.expectEqual(min(u8, "a"), 'a');
|
|
}
|
|
|
|
/// Returns the largest number in a slice. O(n).
|
|
/// `slice` must not be empty.
|
|
pub fn max(comptime T: type, slice: []const T) T {
|
|
assert(slice.len > 0);
|
|
var best = slice[0];
|
|
for (slice[1..]) |item| {
|
|
best = @max(best, item);
|
|
}
|
|
return best;
|
|
}
|
|
|
|
test max {
|
|
try testing.expectEqual(max(u8, "abcdefg"), 'g');
|
|
try testing.expectEqual(max(u8, "gabcdef"), 'g');
|
|
try testing.expectEqual(max(u8, "g"), 'g');
|
|
}
|
|
|
|
/// Finds the smallest and largest number in a slice. O(n).
|
|
/// Returns an anonymous struct with the fields `min` and `max`.
|
|
/// `slice` must not be empty.
|
|
pub fn minMax(comptime T: type, slice: []const T) struct { T, T } {
|
|
assert(slice.len > 0);
|
|
var running_minimum = slice[0];
|
|
var running_maximum = slice[0];
|
|
for (slice[1..]) |item| {
|
|
running_minimum = @min(running_minimum, item);
|
|
running_maximum = @max(running_maximum, item);
|
|
}
|
|
return .{ running_minimum, running_maximum };
|
|
}
|
|
|
|
test minMax {
|
|
{
|
|
const actual_min, const actual_max = minMax(u8, "abcdefg");
|
|
try testing.expectEqual(@as(u8, 'a'), actual_min);
|
|
try testing.expectEqual(@as(u8, 'g'), actual_max);
|
|
}
|
|
{
|
|
const actual_min, const actual_max = minMax(u8, "bcdefga");
|
|
try testing.expectEqual(@as(u8, 'a'), actual_min);
|
|
try testing.expectEqual(@as(u8, 'g'), actual_max);
|
|
}
|
|
{
|
|
const actual_min, const actual_max = minMax(u8, "a");
|
|
try testing.expectEqual(@as(u8, 'a'), actual_min);
|
|
try testing.expectEqual(@as(u8, 'a'), actual_max);
|
|
}
|
|
}
|
|
|
|
/// Returns the index of the smallest number in a slice. O(n).
|
|
/// `slice` must not be empty.
|
|
pub fn indexOfMin(comptime T: type, slice: []const T) usize {
|
|
assert(slice.len > 0);
|
|
var best = slice[0];
|
|
var index: usize = 0;
|
|
for (slice[1..], 0..) |item, i| {
|
|
if (item < best) {
|
|
best = item;
|
|
index = i + 1;
|
|
}
|
|
}
|
|
return index;
|
|
}
|
|
|
|
test indexOfMin {
|
|
try testing.expectEqual(indexOfMin(u8, "abcdefg"), 0);
|
|
try testing.expectEqual(indexOfMin(u8, "bcdefga"), 6);
|
|
try testing.expectEqual(indexOfMin(u8, "a"), 0);
|
|
}
|
|
|
|
/// Returns the index of the largest number in a slice. O(n).
|
|
/// `slice` must not be empty.
|
|
pub fn indexOfMax(comptime T: type, slice: []const T) usize {
|
|
assert(slice.len > 0);
|
|
var best = slice[0];
|
|
var index: usize = 0;
|
|
for (slice[1..], 0..) |item, i| {
|
|
if (item > best) {
|
|
best = item;
|
|
index = i + 1;
|
|
}
|
|
}
|
|
return index;
|
|
}
|
|
|
|
test indexOfMax {
|
|
try testing.expectEqual(indexOfMax(u8, "abcdefg"), 6);
|
|
try testing.expectEqual(indexOfMax(u8, "gabcdef"), 0);
|
|
try testing.expectEqual(indexOfMax(u8, "a"), 0);
|
|
}
|
|
|
|
/// Finds the indices of the smallest and largest number in a slice. O(n).
|
|
/// Returns the indices of the smallest and largest numbers in that order.
|
|
/// `slice` must not be empty.
|
|
pub fn indexOfMinMax(comptime T: type, slice: []const T) struct { usize, usize } {
|
|
assert(slice.len > 0);
|
|
var minVal = slice[0];
|
|
var maxVal = slice[0];
|
|
var minIdx: usize = 0;
|
|
var maxIdx: usize = 0;
|
|
for (slice[1..], 0..) |item, i| {
|
|
if (item < minVal) {
|
|
minVal = item;
|
|
minIdx = i + 1;
|
|
}
|
|
if (item > maxVal) {
|
|
maxVal = item;
|
|
maxIdx = i + 1;
|
|
}
|
|
}
|
|
return .{ minIdx, maxIdx };
|
|
}
|
|
|
|
test indexOfMinMax {
|
|
try testing.expectEqual(.{ 0, 6 }, indexOfMinMax(u8, "abcdefg"));
|
|
try testing.expectEqual(.{ 1, 0 }, indexOfMinMax(u8, "gabcdef"));
|
|
try testing.expectEqual(.{ 0, 0 }, indexOfMinMax(u8, "a"));
|
|
}
|
|
|
|
pub fn swap(comptime T: type, a: *T, b: *T) void {
|
|
const tmp = a.*;
|
|
a.* = b.*;
|
|
b.* = tmp;
|
|
}
|
|
|
|
inline fn reverseVector(comptime N: usize, comptime T: type, a: []T) [N]T {
|
|
var res: [N]T = undefined;
|
|
inline for (0..N) |i| {
|
|
res[i] = a[N - i - 1];
|
|
}
|
|
return res;
|
|
}
|
|
|
|
/// In-place order reversal of a slice
|
|
pub fn reverse(comptime T: type, items: []T) void {
|
|
var i: usize = 0;
|
|
const end = items.len / 2;
|
|
if (backend_supports_vectors and
|
|
!@inComptime() and
|
|
@bitSizeOf(T) > 0 and
|
|
std.math.isPowerOfTwo(@bitSizeOf(T)))
|
|
{
|
|
if (std.simd.suggestVectorLength(T)) |simd_size| {
|
|
if (simd_size <= end) {
|
|
const simd_end = end - (simd_size - 1);
|
|
while (i < simd_end) : (i += simd_size) {
|
|
const left_slice = items[i .. i + simd_size];
|
|
const right_slice = items[items.len - i - simd_size .. items.len - i];
|
|
|
|
const left_shuffled: [simd_size]T = reverseVector(simd_size, T, left_slice);
|
|
const right_shuffled: [simd_size]T = reverseVector(simd_size, T, right_slice);
|
|
|
|
@memcpy(right_slice, &left_shuffled);
|
|
@memcpy(left_slice, &right_shuffled);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
while (i < end) : (i += 1) {
|
|
swap(T, &items[i], &items[items.len - i - 1]);
|
|
}
|
|
}
|
|
|
|
test reverse {
|
|
{
|
|
var arr = [_]i32{ 5, 3, 1, 2, 4 };
|
|
reverse(i32, arr[0..]);
|
|
try testing.expectEqualSlices(i32, &arr, &.{ 4, 2, 1, 3, 5 });
|
|
}
|
|
{
|
|
var arr = [_]u0{};
|
|
reverse(u0, arr[0..]);
|
|
try testing.expectEqualSlices(u0, &arr, &.{});
|
|
}
|
|
{
|
|
var arr = [_]i64{ 19, 17, 15, 13, 11, 9, 7, 5, 3, 1, 2, 4, 6, 8, 10, 12, 14, 16, 18 };
|
|
reverse(i64, arr[0..]);
|
|
try testing.expectEqualSlices(i64, &arr, &.{ 18, 16, 14, 12, 10, 8, 6, 4, 2, 1, 3, 5, 7, 9, 11, 13, 15, 17, 19 });
|
|
}
|
|
{
|
|
var arr = [_][]const u8{ "a", "b", "c", "d" };
|
|
reverse([]const u8, arr[0..]);
|
|
try testing.expectEqualSlices([]const u8, &arr, &.{ "d", "c", "b", "a" });
|
|
}
|
|
{
|
|
const MyType = union(enum) {
|
|
a: [3]u8,
|
|
b: u24,
|
|
c,
|
|
};
|
|
var arr = [_]MyType{ .{ .a = .{ 0, 0, 0 } }, .{ .b = 0 }, .c };
|
|
reverse(MyType, arr[0..]);
|
|
try testing.expectEqualSlices(MyType, &arr, &([_]MyType{ .c, .{ .b = 0 }, .{ .a = .{ 0, 0, 0 } } }));
|
|
}
|
|
}
|
|
fn ReverseIterator(comptime T: type) type {
|
|
const Pointer = blk: {
|
|
switch (@typeInfo(T)) {
|
|
.pointer => |ptr_info| switch (ptr_info.size) {
|
|
.One => switch (@typeInfo(ptr_info.child)) {
|
|
.array => |array_info| {
|
|
var new_ptr_info = ptr_info;
|
|
new_ptr_info.size = .Many;
|
|
new_ptr_info.child = array_info.child;
|
|
new_ptr_info.sentinel = array_info.sentinel;
|
|
break :blk @Type(.{ .pointer = new_ptr_info });
|
|
},
|
|
else => {},
|
|
},
|
|
.Slice => {
|
|
var new_ptr_info = ptr_info;
|
|
new_ptr_info.size = .Many;
|
|
break :blk @Type(.{ .pointer = new_ptr_info });
|
|
},
|
|
else => {},
|
|
},
|
|
else => {},
|
|
}
|
|
@compileError("expected slice or pointer to array, found '" ++ @typeName(T) ++ "'");
|
|
};
|
|
const Element = std.meta.Elem(Pointer);
|
|
const ElementPointer = @Type(.{ .pointer = ptr: {
|
|
var ptr = @typeInfo(Pointer).pointer;
|
|
ptr.size = .One;
|
|
ptr.child = Element;
|
|
ptr.sentinel = null;
|
|
break :ptr ptr;
|
|
} });
|
|
return struct {
|
|
ptr: Pointer,
|
|
index: usize,
|
|
pub fn next(self: *@This()) ?Element {
|
|
if (self.index == 0) return null;
|
|
self.index -= 1;
|
|
return self.ptr[self.index];
|
|
}
|
|
pub fn nextPtr(self: *@This()) ?ElementPointer {
|
|
if (self.index == 0) return null;
|
|
self.index -= 1;
|
|
return &self.ptr[self.index];
|
|
}
|
|
};
|
|
}
|
|
|
|
/// Iterates over a slice in reverse.
|
|
pub fn reverseIterator(slice: anytype) ReverseIterator(@TypeOf(slice)) {
|
|
return .{ .ptr = slice.ptr, .index = slice.len };
|
|
}
|
|
|
|
test reverseIterator {
|
|
{
|
|
var it = reverseIterator("abc");
|
|
try testing.expectEqual(@as(?u8, 'c'), it.next());
|
|
try testing.expectEqual(@as(?u8, 'b'), it.next());
|
|
try testing.expectEqual(@as(?u8, 'a'), it.next());
|
|
try testing.expectEqual(@as(?u8, null), it.next());
|
|
}
|
|
{
|
|
var array = [2]i32{ 3, 7 };
|
|
const slice: []const i32 = &array;
|
|
var it = reverseIterator(slice);
|
|
try testing.expectEqual(@as(?i32, 7), it.next());
|
|
try testing.expectEqual(@as(?i32, 3), it.next());
|
|
try testing.expectEqual(@as(?i32, null), it.next());
|
|
|
|
it = reverseIterator(slice);
|
|
try testing.expect(*const i32 == @TypeOf(it.nextPtr().?));
|
|
try testing.expectEqual(@as(?i32, 7), it.nextPtr().?.*);
|
|
try testing.expectEqual(@as(?i32, 3), it.nextPtr().?.*);
|
|
try testing.expectEqual(@as(?*const i32, null), it.nextPtr());
|
|
|
|
const mut_slice: []i32 = &array;
|
|
var mut_it = reverseIterator(mut_slice);
|
|
mut_it.nextPtr().?.* += 1;
|
|
mut_it.nextPtr().?.* += 2;
|
|
try testing.expectEqual([2]i32{ 5, 8 }, array);
|
|
}
|
|
{
|
|
var array = [2]i32{ 3, 7 };
|
|
const ptr_to_array: *const [2]i32 = &array;
|
|
var it = reverseIterator(ptr_to_array);
|
|
try testing.expectEqual(@as(?i32, 7), it.next());
|
|
try testing.expectEqual(@as(?i32, 3), it.next());
|
|
try testing.expectEqual(@as(?i32, null), it.next());
|
|
|
|
it = reverseIterator(ptr_to_array);
|
|
try testing.expect(*const i32 == @TypeOf(it.nextPtr().?));
|
|
try testing.expectEqual(@as(?i32, 7), it.nextPtr().?.*);
|
|
try testing.expectEqual(@as(?i32, 3), it.nextPtr().?.*);
|
|
try testing.expectEqual(@as(?*const i32, null), it.nextPtr());
|
|
|
|
const mut_ptr_to_array: *[2]i32 = &array;
|
|
var mut_it = reverseIterator(mut_ptr_to_array);
|
|
mut_it.nextPtr().?.* += 1;
|
|
mut_it.nextPtr().?.* += 2;
|
|
try testing.expectEqual([2]i32{ 5, 8 }, array);
|
|
}
|
|
}
|
|
|
|
/// In-place rotation of the values in an array ([0 1 2 3] becomes [1 2 3 0] if we rotate by 1)
|
|
/// Assumes 0 <= amount <= items.len
|
|
pub fn rotate(comptime T: type, items: []T, amount: usize) void {
|
|
reverse(T, items[0..amount]);
|
|
reverse(T, items[amount..]);
|
|
reverse(T, items);
|
|
}
|
|
|
|
test rotate {
|
|
var arr = [_]i32{ 5, 3, 1, 2, 4 };
|
|
rotate(i32, arr[0..], 2);
|
|
|
|
try testing.expect(eql(i32, &arr, &[_]i32{ 1, 2, 4, 5, 3 }));
|
|
}
|
|
|
|
/// Replace needle with replacement as many times as possible, writing to an output buffer which is assumed to be of
|
|
/// appropriate size. Use replacementSize to calculate an appropriate buffer size.
|
|
/// The needle must not be empty.
|
|
/// Returns the number of replacements made.
|
|
pub fn replace(comptime T: type, input: []const T, needle: []const T, replacement: []const T, output: []T) usize {
|
|
// Empty needle will loop until output buffer overflows.
|
|
assert(needle.len > 0);
|
|
|
|
var i: usize = 0;
|
|
var slide: usize = 0;
|
|
var replacements: usize = 0;
|
|
while (slide < input.len) {
|
|
if (mem.startsWith(T, input[slide..], needle)) {
|
|
@memcpy(output[i..][0..replacement.len], replacement);
|
|
i += replacement.len;
|
|
slide += needle.len;
|
|
replacements += 1;
|
|
} else {
|
|
output[i] = input[slide];
|
|
i += 1;
|
|
slide += 1;
|
|
}
|
|
}
|
|
|
|
return replacements;
|
|
}
|
|
|
|
test replace {
|
|
var output: [29]u8 = undefined;
|
|
var replacements = replace(u8, "All your base are belong to us", "base", "Zig", output[0..]);
|
|
var expected: []const u8 = "All your Zig are belong to us";
|
|
try testing.expect(replacements == 1);
|
|
try testing.expectEqualStrings(expected, output[0..expected.len]);
|
|
|
|
replacements = replace(u8, "Favor reading code over writing code.", "code", "", output[0..]);
|
|
expected = "Favor reading over writing .";
|
|
try testing.expect(replacements == 2);
|
|
try testing.expectEqualStrings(expected, output[0..expected.len]);
|
|
|
|
// Empty needle is not allowed but input may be empty.
|
|
replacements = replace(u8, "", "x", "y", output[0..0]);
|
|
expected = "";
|
|
try testing.expect(replacements == 0);
|
|
try testing.expectEqualStrings(expected, output[0..expected.len]);
|
|
|
|
// Adjacent replacements.
|
|
|
|
replacements = replace(u8, "\\n\\n", "\\n", "\n", output[0..]);
|
|
expected = "\n\n";
|
|
try testing.expect(replacements == 2);
|
|
try testing.expectEqualStrings(expected, output[0..expected.len]);
|
|
|
|
replacements = replace(u8, "abbba", "b", "cd", output[0..]);
|
|
expected = "acdcdcda";
|
|
try testing.expect(replacements == 3);
|
|
try testing.expectEqualStrings(expected, output[0..expected.len]);
|
|
}
|
|
|
|
/// Replace all occurrences of `match` with `replacement`.
|
|
pub fn replaceScalar(comptime T: type, slice: []T, match: T, replacement: T) void {
|
|
for (slice) |*e| {
|
|
if (e.* == match)
|
|
e.* = replacement;
|
|
}
|
|
}
|
|
|
|
/// Collapse consecutive duplicate elements into one entry.
|
|
pub fn collapseRepeatsLen(comptime T: type, slice: []T, elem: T) usize {
|
|
if (slice.len == 0) return 0;
|
|
var write_idx: usize = 1;
|
|
var read_idx: usize = 1;
|
|
while (read_idx < slice.len) : (read_idx += 1) {
|
|
if (slice[read_idx - 1] != elem or slice[read_idx] != elem) {
|
|
slice[write_idx] = slice[read_idx];
|
|
write_idx += 1;
|
|
}
|
|
}
|
|
return write_idx;
|
|
}
|
|
|
|
/// Collapse consecutive duplicate elements into one entry.
|
|
pub fn collapseRepeats(comptime T: type, slice: []T, elem: T) []T {
|
|
return slice[0..collapseRepeatsLen(T, slice, elem)];
|
|
}
|
|
|
|
fn testCollapseRepeats(str: []const u8, elem: u8, expected: []const u8) !void {
|
|
const mutable = try std.testing.allocator.dupe(u8, str);
|
|
defer std.testing.allocator.free(mutable);
|
|
try testing.expect(std.mem.eql(u8, collapseRepeats(u8, mutable, elem), expected));
|
|
}
|
|
test collapseRepeats {
|
|
try testCollapseRepeats("", '/', "");
|
|
try testCollapseRepeats("a", '/', "a");
|
|
try testCollapseRepeats("/", '/', "/");
|
|
try testCollapseRepeats("//", '/', "/");
|
|
try testCollapseRepeats("/a", '/', "/a");
|
|
try testCollapseRepeats("//a", '/', "/a");
|
|
try testCollapseRepeats("a/", '/', "a/");
|
|
try testCollapseRepeats("a//", '/', "a/");
|
|
try testCollapseRepeats("a/a", '/', "a/a");
|
|
try testCollapseRepeats("a//a", '/', "a/a");
|
|
try testCollapseRepeats("//a///a////", '/', "/a/a/");
|
|
}
|
|
|
|
/// Calculate the size needed in an output buffer to perform a replacement.
|
|
/// The needle must not be empty.
|
|
pub fn replacementSize(comptime T: type, input: []const T, needle: []const T, replacement: []const T) usize {
|
|
// Empty needle will loop forever.
|
|
assert(needle.len > 0);
|
|
|
|
var i: usize = 0;
|
|
var size: usize = input.len;
|
|
while (i < input.len) {
|
|
if (mem.startsWith(T, input[i..], needle)) {
|
|
size = size - needle.len + replacement.len;
|
|
i += needle.len;
|
|
} else {
|
|
i += 1;
|
|
}
|
|
}
|
|
|
|
return size;
|
|
}
|
|
|
|
test replacementSize {
|
|
try testing.expect(replacementSize(u8, "All your base are belong to us", "base", "Zig") == 29);
|
|
try testing.expect(replacementSize(u8, "Favor reading code over writing code.", "code", "") == 29);
|
|
try testing.expect(replacementSize(u8, "Only one obvious way to do things.", "things.", "things in Zig.") == 41);
|
|
|
|
// Empty needle is not allowed but input may be empty.
|
|
try testing.expect(replacementSize(u8, "", "x", "y") == 0);
|
|
|
|
// Adjacent replacements.
|
|
try testing.expect(replacementSize(u8, "\\n\\n", "\\n", "\n") == 2);
|
|
try testing.expect(replacementSize(u8, "abbba", "b", "cd") == 8);
|
|
}
|
|
|
|
/// Perform a replacement on an allocated buffer of pre-determined size. Caller must free returned memory.
|
|
pub fn replaceOwned(comptime T: type, allocator: Allocator, input: []const T, needle: []const T, replacement: []const T) Allocator.Error![]T {
|
|
const output = try allocator.alloc(T, replacementSize(T, input, needle, replacement));
|
|
_ = replace(T, input, needle, replacement, output);
|
|
return output;
|
|
}
|
|
|
|
test replaceOwned {
|
|
const gpa = std.testing.allocator;
|
|
|
|
const base_replace = replaceOwned(u8, gpa, "All your base are belong to us", "base", "Zig") catch @panic("out of memory");
|
|
defer gpa.free(base_replace);
|
|
try testing.expect(eql(u8, base_replace, "All your Zig are belong to us"));
|
|
|
|
const zen_replace = replaceOwned(u8, gpa, "Favor reading code over writing code.", " code", "") catch @panic("out of memory");
|
|
defer gpa.free(zen_replace);
|
|
try testing.expect(eql(u8, zen_replace, "Favor reading over writing."));
|
|
}
|
|
|
|
/// Converts a little-endian integer to host endianness.
|
|
pub fn littleToNative(comptime T: type, x: T) T {
|
|
return switch (native_endian) {
|
|
.little => x,
|
|
.big => @byteSwap(x),
|
|
};
|
|
}
|
|
|
|
/// Converts a big-endian integer to host endianness.
|
|
pub fn bigToNative(comptime T: type, x: T) T {
|
|
return switch (native_endian) {
|
|
.little => @byteSwap(x),
|
|
.big => x,
|
|
};
|
|
}
|
|
|
|
/// Converts an integer from specified endianness to host endianness.
|
|
pub fn toNative(comptime T: type, x: T, endianness_of_x: Endian) T {
|
|
return switch (endianness_of_x) {
|
|
.little => littleToNative(T, x),
|
|
.big => bigToNative(T, x),
|
|
};
|
|
}
|
|
|
|
/// Converts an integer which has host endianness to the desired endianness.
|
|
pub fn nativeTo(comptime T: type, x: T, desired_endianness: Endian) T {
|
|
return switch (desired_endianness) {
|
|
.little => nativeToLittle(T, x),
|
|
.big => nativeToBig(T, x),
|
|
};
|
|
}
|
|
|
|
/// Converts an integer which has host endianness to little endian.
|
|
pub fn nativeToLittle(comptime T: type, x: T) T {
|
|
return switch (native_endian) {
|
|
.little => x,
|
|
.big => @byteSwap(x),
|
|
};
|
|
}
|
|
|
|
/// Converts an integer which has host endianness to big endian.
|
|
pub fn nativeToBig(comptime T: type, x: T) T {
|
|
return switch (native_endian) {
|
|
.little => @byteSwap(x),
|
|
.big => x,
|
|
};
|
|
}
|
|
|
|
/// Returns the number of elements that, if added to the given pointer, align it
|
|
/// to a multiple of the given quantity, or `null` if one of the following
|
|
/// conditions is met:
|
|
/// - The aligned pointer would not fit the address space,
|
|
/// - The delta required to align the pointer is not a multiple of the pointee's
|
|
/// type.
|
|
pub fn alignPointerOffset(ptr: anytype, align_to: usize) ?usize {
|
|
assert(isValidAlign(align_to));
|
|
|
|
const T = @TypeOf(ptr);
|
|
const info = @typeInfo(T);
|
|
if (info != .pointer or info.pointer.size != .Many)
|
|
@compileError("expected many item pointer, got " ++ @typeName(T));
|
|
|
|
// Do nothing if the pointer is already well-aligned.
|
|
if (align_to <= info.pointer.alignment)
|
|
return 0;
|
|
|
|
// Calculate the aligned base address with an eye out for overflow.
|
|
const addr = @intFromPtr(ptr);
|
|
var ov = @addWithOverflow(addr, align_to - 1);
|
|
if (ov[1] != 0) return null;
|
|
ov[0] &= ~@as(usize, align_to - 1);
|
|
|
|
// The delta is expressed in terms of bytes, turn it into a number of child
|
|
// type elements.
|
|
const delta = ov[0] - addr;
|
|
const pointee_size = @sizeOf(info.pointer.child);
|
|
if (delta % pointee_size != 0) return null;
|
|
return delta / pointee_size;
|
|
}
|
|
|
|
/// Aligns a given pointer value to a specified alignment factor.
|
|
/// Returns an aligned pointer or null if one of the following conditions is
|
|
/// met:
|
|
/// - The aligned pointer would not fit the address space,
|
|
/// - The delta required to align the pointer is not a multiple of the pointee's
|
|
/// type.
|
|
pub fn alignPointer(ptr: anytype, align_to: usize) ?@TypeOf(ptr) {
|
|
const adjust_off = alignPointerOffset(ptr, align_to) orelse return null;
|
|
// Avoid the use of ptrFromInt to avoid losing the pointer provenance info.
|
|
return @alignCast(ptr + adjust_off);
|
|
}
|
|
|
|
test alignPointer {
|
|
const S = struct {
|
|
fn checkAlign(comptime T: type, base: usize, align_to: usize, expected: usize) !void {
|
|
const ptr: T = @ptrFromInt(base);
|
|
const aligned = alignPointer(ptr, align_to);
|
|
try testing.expectEqual(expected, @intFromPtr(aligned));
|
|
}
|
|
};
|
|
|
|
try S.checkAlign([*]u8, 0x123, 0x200, 0x200);
|
|
try S.checkAlign([*]align(4) u8, 0x10, 2, 0x10);
|
|
try S.checkAlign([*]u32, 0x10, 2, 0x10);
|
|
try S.checkAlign([*]u32, 0x4, 16, 0x10);
|
|
// Misaligned.
|
|
try S.checkAlign([*]align(1) u32, 0x3, 2, 0);
|
|
// Overflow.
|
|
try S.checkAlign([*]u32, math.maxInt(usize) - 3, 8, 0);
|
|
}
|
|
|
|
fn CopyPtrAttrs(
|
|
comptime source: type,
|
|
comptime size: std.builtin.Type.Pointer.Size,
|
|
comptime child: type,
|
|
) type {
|
|
const info = @typeInfo(source).pointer;
|
|
return @Type(.{
|
|
.pointer = .{
|
|
.size = size,
|
|
.is_const = info.is_const,
|
|
.is_volatile = info.is_volatile,
|
|
.is_allowzero = info.is_allowzero,
|
|
.alignment = info.alignment,
|
|
.address_space = info.address_space,
|
|
.child = child,
|
|
.sentinel = null,
|
|
},
|
|
});
|
|
}
|
|
|
|
fn AsBytesReturnType(comptime P: type) type {
|
|
const pointer = @typeInfo(P).pointer;
|
|
assert(pointer.size == .One);
|
|
const size = @sizeOf(pointer.child);
|
|
return CopyPtrAttrs(P, .One, [size]u8);
|
|
}
|
|
|
|
/// Given a pointer to a single item, returns a slice of the underlying bytes, preserving pointer attributes.
|
|
pub fn asBytes(ptr: anytype) AsBytesReturnType(@TypeOf(ptr)) {
|
|
return @ptrCast(@alignCast(ptr));
|
|
}
|
|
|
|
test asBytes {
|
|
const deadbeef = @as(u32, 0xDEADBEEF);
|
|
const deadbeef_bytes = switch (native_endian) {
|
|
.big => "\xDE\xAD\xBE\xEF",
|
|
.little => "\xEF\xBE\xAD\xDE",
|
|
};
|
|
|
|
try testing.expect(eql(u8, asBytes(&deadbeef), deadbeef_bytes));
|
|
|
|
var codeface = @as(u32, 0xC0DEFACE);
|
|
for (asBytes(&codeface)) |*b|
|
|
b.* = 0;
|
|
try testing.expect(codeface == 0);
|
|
|
|
const S = packed struct {
|
|
a: u8,
|
|
b: u8,
|
|
c: u8,
|
|
d: u8,
|
|
};
|
|
|
|
const inst = S{
|
|
.a = 0xBE,
|
|
.b = 0xEF,
|
|
.c = 0xDE,
|
|
.d = 0xA1,
|
|
};
|
|
switch (native_endian) {
|
|
.little => {
|
|
try testing.expect(eql(u8, asBytes(&inst), "\xBE\xEF\xDE\xA1"));
|
|
},
|
|
.big => {
|
|
try testing.expect(eql(u8, asBytes(&inst), "\xA1\xDE\xEF\xBE"));
|
|
},
|
|
}
|
|
|
|
const ZST = struct {};
|
|
const zero = ZST{};
|
|
try testing.expect(eql(u8, asBytes(&zero), ""));
|
|
}
|
|
|
|
test "asBytes preserves pointer attributes" {
|
|
const inArr: u32 align(16) = 0xDEADBEEF;
|
|
const inPtr = @as(*align(16) const volatile u32, @ptrCast(&inArr));
|
|
const outSlice = asBytes(inPtr);
|
|
|
|
const in = @typeInfo(@TypeOf(inPtr)).pointer;
|
|
const out = @typeInfo(@TypeOf(outSlice)).pointer;
|
|
|
|
try testing.expectEqual(in.is_const, out.is_const);
|
|
try testing.expectEqual(in.is_volatile, out.is_volatile);
|
|
try testing.expectEqual(in.is_allowzero, out.is_allowzero);
|
|
try testing.expectEqual(in.alignment, out.alignment);
|
|
}
|
|
|
|
/// Given any value, returns a copy of its bytes in an array.
|
|
pub fn toBytes(value: anytype) [@sizeOf(@TypeOf(value))]u8 {
|
|
return asBytes(&value).*;
|
|
}
|
|
|
|
test toBytes {
|
|
var my_bytes = toBytes(@as(u32, 0x12345678));
|
|
switch (native_endian) {
|
|
.big => try testing.expect(eql(u8, &my_bytes, "\x12\x34\x56\x78")),
|
|
.little => try testing.expect(eql(u8, &my_bytes, "\x78\x56\x34\x12")),
|
|
}
|
|
|
|
my_bytes[0] = '\x99';
|
|
switch (native_endian) {
|
|
.big => try testing.expect(eql(u8, &my_bytes, "\x99\x34\x56\x78")),
|
|
.little => try testing.expect(eql(u8, &my_bytes, "\x99\x56\x34\x12")),
|
|
}
|
|
}
|
|
|
|
fn BytesAsValueReturnType(comptime T: type, comptime B: type) type {
|
|
return CopyPtrAttrs(B, .One, T);
|
|
}
|
|
|
|
/// Given a pointer to an array of bytes, returns a pointer to a value of the specified type
|
|
/// backed by those bytes, preserving pointer attributes.
|
|
pub fn bytesAsValue(comptime T: type, bytes: anytype) BytesAsValueReturnType(T, @TypeOf(bytes)) {
|
|
return @ptrCast(bytes);
|
|
}
|
|
|
|
test bytesAsValue {
|
|
const deadbeef = @as(u32, 0xDEADBEEF);
|
|
const deadbeef_bytes = switch (native_endian) {
|
|
.big => "\xDE\xAD\xBE\xEF",
|
|
.little => "\xEF\xBE\xAD\xDE",
|
|
};
|
|
|
|
try testing.expect(deadbeef == bytesAsValue(u32, deadbeef_bytes).*);
|
|
|
|
var codeface_bytes: [4]u8 = switch (native_endian) {
|
|
.big => "\xC0\xDE\xFA\xCE",
|
|
.little => "\xCE\xFA\xDE\xC0",
|
|
}.*;
|
|
const codeface = bytesAsValue(u32, &codeface_bytes);
|
|
try testing.expect(codeface.* == 0xC0DEFACE);
|
|
codeface.* = 0;
|
|
for (codeface_bytes) |b|
|
|
try testing.expect(b == 0);
|
|
|
|
const S = packed struct {
|
|
a: u8,
|
|
b: u8,
|
|
c: u8,
|
|
d: u8,
|
|
};
|
|
|
|
const inst = S{
|
|
.a = 0xBE,
|
|
.b = 0xEF,
|
|
.c = 0xDE,
|
|
.d = 0xA1,
|
|
};
|
|
const inst_bytes = switch (native_endian) {
|
|
.little => "\xBE\xEF\xDE\xA1",
|
|
.big => "\xA1\xDE\xEF\xBE",
|
|
};
|
|
const inst2 = bytesAsValue(S, inst_bytes);
|
|
try testing.expect(std.meta.eql(inst, inst2.*));
|
|
}
|
|
|
|
test "bytesAsValue preserves pointer attributes" {
|
|
const inArr align(16) = [4]u8{ 0xDE, 0xAD, 0xBE, 0xEF };
|
|
const inSlice = @as(*align(16) const volatile [4]u8, @ptrCast(&inArr))[0..];
|
|
const outPtr = bytesAsValue(u32, inSlice);
|
|
|
|
const in = @typeInfo(@TypeOf(inSlice)).pointer;
|
|
const out = @typeInfo(@TypeOf(outPtr)).pointer;
|
|
|
|
try testing.expectEqual(in.is_const, out.is_const);
|
|
try testing.expectEqual(in.is_volatile, out.is_volatile);
|
|
try testing.expectEqual(in.is_allowzero, out.is_allowzero);
|
|
try testing.expectEqual(in.alignment, out.alignment);
|
|
}
|
|
|
|
/// Given a pointer to an array of bytes, returns a value of the specified type backed by a
|
|
/// copy of those bytes.
|
|
pub fn bytesToValue(comptime T: type, bytes: anytype) T {
|
|
return bytesAsValue(T, bytes).*;
|
|
}
|
|
test bytesToValue {
|
|
const deadbeef_bytes = switch (native_endian) {
|
|
.big => "\xDE\xAD\xBE\xEF",
|
|
.little => "\xEF\xBE\xAD\xDE",
|
|
};
|
|
|
|
const deadbeef = bytesToValue(u32, deadbeef_bytes);
|
|
try testing.expect(deadbeef == @as(u32, 0xDEADBEEF));
|
|
}
|
|
|
|
fn BytesAsSliceReturnType(comptime T: type, comptime bytesType: type) type {
|
|
return CopyPtrAttrs(bytesType, .Slice, T);
|
|
}
|
|
|
|
/// Given a slice of bytes, returns a slice of the specified type
|
|
/// backed by those bytes, preserving pointer attributes.
|
|
pub fn bytesAsSlice(comptime T: type, bytes: anytype) BytesAsSliceReturnType(T, @TypeOf(bytes)) {
|
|
// let's not give an undefined pointer to @ptrCast
|
|
// it may be equal to zero and fail a null check
|
|
if (bytes.len == 0) {
|
|
return &[0]T{};
|
|
}
|
|
|
|
const cast_target = CopyPtrAttrs(@TypeOf(bytes), .Many, T);
|
|
|
|
return @as(cast_target, @ptrCast(bytes))[0..@divExact(bytes.len, @sizeOf(T))];
|
|
}
|
|
|
|
test bytesAsSlice {
|
|
{
|
|
const bytes = [_]u8{ 0xDE, 0xAD, 0xBE, 0xEF };
|
|
const slice = bytesAsSlice(u16, bytes[0..]);
|
|
try testing.expect(slice.len == 2);
|
|
try testing.expect(bigToNative(u16, slice[0]) == 0xDEAD);
|
|
try testing.expect(bigToNative(u16, slice[1]) == 0xBEEF);
|
|
}
|
|
{
|
|
const bytes = [_]u8{ 0xDE, 0xAD, 0xBE, 0xEF };
|
|
var runtime_zero: usize = 0;
|
|
_ = &runtime_zero;
|
|
const slice = bytesAsSlice(u16, bytes[runtime_zero..]);
|
|
try testing.expect(slice.len == 2);
|
|
try testing.expect(bigToNative(u16, slice[0]) == 0xDEAD);
|
|
try testing.expect(bigToNative(u16, slice[1]) == 0xBEEF);
|
|
}
|
|
}
|
|
|
|
test "bytesAsSlice keeps pointer alignment" {
|
|
{
|
|
var bytes = [_]u8{ 0x01, 0x02, 0x03, 0x04 };
|
|
const numbers = bytesAsSlice(u32, bytes[0..]);
|
|
try comptime testing.expect(@TypeOf(numbers) == []align(@alignOf(@TypeOf(bytes))) u32);
|
|
}
|
|
{
|
|
var bytes = [_]u8{ 0x01, 0x02, 0x03, 0x04 };
|
|
var runtime_zero: usize = 0;
|
|
_ = &runtime_zero;
|
|
const numbers = bytesAsSlice(u32, bytes[runtime_zero..]);
|
|
try comptime testing.expect(@TypeOf(numbers) == []align(@alignOf(@TypeOf(bytes))) u32);
|
|
}
|
|
}
|
|
|
|
test "bytesAsSlice on a packed struct" {
|
|
const F = packed struct {
|
|
a: u8,
|
|
};
|
|
|
|
const b: [1]u8 = .{9};
|
|
const f = bytesAsSlice(F, &b);
|
|
try testing.expect(f[0].a == 9);
|
|
}
|
|
|
|
test "bytesAsSlice with specified alignment" {
|
|
var bytes align(4) = [_]u8{
|
|
0x33,
|
|
0x33,
|
|
0x33,
|
|
0x33,
|
|
};
|
|
const slice: []u32 = std.mem.bytesAsSlice(u32, bytes[0..]);
|
|
try testing.expect(slice[0] == 0x33333333);
|
|
}
|
|
|
|
test "bytesAsSlice preserves pointer attributes" {
|
|
const inArr align(16) = [4]u8{ 0xDE, 0xAD, 0xBE, 0xEF };
|
|
const inSlice = @as(*align(16) const volatile [4]u8, @ptrCast(&inArr))[0..];
|
|
const outSlice = bytesAsSlice(u16, inSlice);
|
|
|
|
const in = @typeInfo(@TypeOf(inSlice)).pointer;
|
|
const out = @typeInfo(@TypeOf(outSlice)).pointer;
|
|
|
|
try testing.expectEqual(in.is_const, out.is_const);
|
|
try testing.expectEqual(in.is_volatile, out.is_volatile);
|
|
try testing.expectEqual(in.is_allowzero, out.is_allowzero);
|
|
try testing.expectEqual(in.alignment, out.alignment);
|
|
}
|
|
|
|
fn SliceAsBytesReturnType(comptime Slice: type) type {
|
|
return CopyPtrAttrs(Slice, .Slice, u8);
|
|
}
|
|
|
|
/// Given a slice, returns a slice of the underlying bytes, preserving pointer attributes.
|
|
pub fn sliceAsBytes(slice: anytype) SliceAsBytesReturnType(@TypeOf(slice)) {
|
|
const Slice = @TypeOf(slice);
|
|
|
|
// a slice of zero-bit values always occupies zero bytes
|
|
if (@sizeOf(std.meta.Elem(Slice)) == 0) return &[0]u8{};
|
|
|
|
// let's not give an undefined pointer to @ptrCast
|
|
// it may be equal to zero and fail a null check
|
|
if (slice.len == 0 and std.meta.sentinel(Slice) == null) return &[0]u8{};
|
|
|
|
const cast_target = CopyPtrAttrs(Slice, .Many, u8);
|
|
|
|
return @as(cast_target, @ptrCast(slice))[0 .. slice.len * @sizeOf(std.meta.Elem(Slice))];
|
|
}
|
|
|
|
test sliceAsBytes {
|
|
const bytes = [_]u16{ 0xDEAD, 0xBEEF };
|
|
const slice = sliceAsBytes(bytes[0..]);
|
|
try testing.expect(slice.len == 4);
|
|
try testing.expect(eql(u8, slice, switch (native_endian) {
|
|
.big => "\xDE\xAD\xBE\xEF",
|
|
.little => "\xAD\xDE\xEF\xBE",
|
|
}));
|
|
}
|
|
|
|
test "sliceAsBytes with sentinel slice" {
|
|
const empty_string: [:0]const u8 = "";
|
|
const bytes = sliceAsBytes(empty_string);
|
|
try testing.expect(bytes.len == 0);
|
|
}
|
|
|
|
test "sliceAsBytes with zero-bit element type" {
|
|
const lots_of_nothing = [1]void{{}} ** 10_000;
|
|
const bytes = sliceAsBytes(&lots_of_nothing);
|
|
try testing.expect(bytes.len == 0);
|
|
}
|
|
|
|
test "sliceAsBytes packed struct at runtime and comptime" {
|
|
const Foo = packed struct {
|
|
a: u4,
|
|
b: u4,
|
|
};
|
|
const S = struct {
|
|
fn doTheTest() !void {
|
|
var foo: Foo = undefined;
|
|
var slice = sliceAsBytes(@as(*[1]Foo, &foo)[0..1]);
|
|
slice[0] = 0x13;
|
|
try testing.expect(foo.a == 0x3);
|
|
try testing.expect(foo.b == 0x1);
|
|
}
|
|
};
|
|
try S.doTheTest();
|
|
try comptime S.doTheTest();
|
|
}
|
|
|
|
test "sliceAsBytes and bytesAsSlice back" {
|
|
try testing.expect(@sizeOf(i32) == 4);
|
|
|
|
var big_thing_array = [_]i32{ 1, 2, 3, 4 };
|
|
const big_thing_slice: []i32 = big_thing_array[0..];
|
|
|
|
const bytes = sliceAsBytes(big_thing_slice);
|
|
try testing.expect(bytes.len == 4 * 4);
|
|
|
|
bytes[4] = 0;
|
|
bytes[5] = 0;
|
|
bytes[6] = 0;
|
|
bytes[7] = 0;
|
|
try testing.expect(big_thing_slice[1] == 0);
|
|
|
|
const big_thing_again = bytesAsSlice(i32, bytes);
|
|
try testing.expect(big_thing_again[2] == 3);
|
|
|
|
big_thing_again[2] = -1;
|
|
try testing.expect(bytes[8] == math.maxInt(u8));
|
|
try testing.expect(bytes[9] == math.maxInt(u8));
|
|
try testing.expect(bytes[10] == math.maxInt(u8));
|
|
try testing.expect(bytes[11] == math.maxInt(u8));
|
|
}
|
|
|
|
test "sliceAsBytes preserves pointer attributes" {
|
|
const inArr align(16) = [2]u16{ 0xDEAD, 0xBEEF };
|
|
const inSlice = @as(*align(16) const volatile [2]u16, @ptrCast(&inArr))[0..];
|
|
const outSlice = sliceAsBytes(inSlice);
|
|
|
|
const in = @typeInfo(@TypeOf(inSlice)).pointer;
|
|
const out = @typeInfo(@TypeOf(outSlice)).pointer;
|
|
|
|
try testing.expectEqual(in.is_const, out.is_const);
|
|
try testing.expectEqual(in.is_volatile, out.is_volatile);
|
|
try testing.expectEqual(in.is_allowzero, out.is_allowzero);
|
|
try testing.expectEqual(in.alignment, out.alignment);
|
|
}
|
|
|
|
/// Round an address down to the next (or current) aligned address.
|
|
/// Unlike `alignForward`, `alignment` can be any positive number, not just a power of 2.
|
|
pub fn alignForwardAnyAlign(comptime T: type, addr: T, alignment: T) T {
|
|
if (isValidAlignGeneric(T, alignment))
|
|
return alignForward(T, addr, alignment);
|
|
assert(alignment != 0);
|
|
return alignBackwardAnyAlign(T, addr + (alignment - 1), alignment);
|
|
}
|
|
|
|
/// Round an address up to the next (or current) aligned address.
|
|
/// The alignment must be a power of 2 and greater than 0.
|
|
/// Asserts that rounding up the address does not cause integer overflow.
|
|
pub fn alignForward(comptime T: type, addr: T, alignment: T) T {
|
|
assert(isValidAlignGeneric(T, alignment));
|
|
return alignBackward(T, addr + (alignment - 1), alignment);
|
|
}
|
|
|
|
pub fn alignForwardLog2(addr: usize, log2_alignment: u8) usize {
|
|
const alignment = @as(usize, 1) << @as(math.Log2Int(usize), @intCast(log2_alignment));
|
|
return alignForward(usize, addr, alignment);
|
|
}
|
|
|
|
/// Force an evaluation of the expression; this tries to prevent
|
|
/// the compiler from optimizing the computation away even if the
|
|
/// result eventually gets discarded.
|
|
// TODO: use @declareSideEffect() when it is available - https://github.com/ziglang/zig/issues/6168
|
|
pub fn doNotOptimizeAway(val: anytype) void {
|
|
if (@inComptime()) return;
|
|
|
|
const max_gp_register_bits = @bitSizeOf(c_long);
|
|
const t = @typeInfo(@TypeOf(val));
|
|
switch (t) {
|
|
.void, .null, .comptime_int, .comptime_float => return,
|
|
.@"enum" => doNotOptimizeAway(@intFromEnum(val)),
|
|
.bool => doNotOptimizeAway(@intFromBool(val)),
|
|
.int => {
|
|
const bits = t.int.bits;
|
|
if (bits <= max_gp_register_bits and builtin.zig_backend != .stage2_c) {
|
|
const val2 = @as(
|
|
std.meta.Int(t.int.signedness, @max(8, std.math.ceilPowerOfTwoAssert(u16, bits))),
|
|
val,
|
|
);
|
|
asm volatile (""
|
|
:
|
|
: [val2] "r" (val2),
|
|
);
|
|
} else doNotOptimizeAway(&val);
|
|
},
|
|
.float => {
|
|
if ((t.float.bits == 32 or t.float.bits == 64) and builtin.zig_backend != .stage2_c) {
|
|
asm volatile (""
|
|
:
|
|
: [val] "rm" (val),
|
|
);
|
|
} else doNotOptimizeAway(&val);
|
|
},
|
|
.pointer => {
|
|
if (builtin.zig_backend == .stage2_c) {
|
|
doNotOptimizeAwayC(val);
|
|
} else {
|
|
asm volatile (""
|
|
:
|
|
: [val] "m" (val),
|
|
: "memory"
|
|
);
|
|
}
|
|
},
|
|
.array => {
|
|
if (t.array.len * @sizeOf(t.array.child) <= 64) {
|
|
for (val) |v| doNotOptimizeAway(v);
|
|
} else doNotOptimizeAway(&val);
|
|
},
|
|
else => doNotOptimizeAway(&val),
|
|
}
|
|
}
|
|
|
|
/// .stage2_c doesn't support asm blocks yet, so use volatile stores instead
|
|
var deopt_target: if (builtin.zig_backend == .stage2_c) u8 else void = undefined;
|
|
fn doNotOptimizeAwayC(ptr: anytype) void {
|
|
const dest = @as(*volatile u8, @ptrCast(&deopt_target));
|
|
for (asBytes(ptr)) |b| {
|
|
dest.* = b;
|
|
}
|
|
dest.* = 0;
|
|
}
|
|
|
|
test doNotOptimizeAway {
|
|
comptime doNotOptimizeAway("test");
|
|
|
|
doNotOptimizeAway(null);
|
|
doNotOptimizeAway(true);
|
|
doNotOptimizeAway(0);
|
|
doNotOptimizeAway(0.0);
|
|
doNotOptimizeAway(@as(u1, 0));
|
|
doNotOptimizeAway(@as(u3, 0));
|
|
doNotOptimizeAway(@as(u8, 0));
|
|
doNotOptimizeAway(@as(u16, 0));
|
|
doNotOptimizeAway(@as(u32, 0));
|
|
doNotOptimizeAway(@as(u64, 0));
|
|
doNotOptimizeAway(@as(u128, 0));
|
|
doNotOptimizeAway(@as(u13, 0));
|
|
doNotOptimizeAway(@as(u37, 0));
|
|
doNotOptimizeAway(@as(u96, 0));
|
|
doNotOptimizeAway(@as(u200, 0));
|
|
doNotOptimizeAway(@as(f32, 0.0));
|
|
doNotOptimizeAway(@as(f64, 0.0));
|
|
doNotOptimizeAway([_]u8{0} ** 4);
|
|
doNotOptimizeAway([_]u8{0} ** 100);
|
|
doNotOptimizeAway(@as(std.builtin.Endian, .little));
|
|
}
|
|
|
|
test alignForward {
|
|
try testing.expect(alignForward(usize, 1, 1) == 1);
|
|
try testing.expect(alignForward(usize, 2, 1) == 2);
|
|
try testing.expect(alignForward(usize, 1, 2) == 2);
|
|
try testing.expect(alignForward(usize, 2, 2) == 2);
|
|
try testing.expect(alignForward(usize, 3, 2) == 4);
|
|
try testing.expect(alignForward(usize, 4, 2) == 4);
|
|
try testing.expect(alignForward(usize, 7, 8) == 8);
|
|
try testing.expect(alignForward(usize, 8, 8) == 8);
|
|
try testing.expect(alignForward(usize, 9, 8) == 16);
|
|
try testing.expect(alignForward(usize, 15, 8) == 16);
|
|
try testing.expect(alignForward(usize, 16, 8) == 16);
|
|
try testing.expect(alignForward(usize, 17, 8) == 24);
|
|
}
|
|
|
|
/// Round an address down to the previous (or current) aligned address.
|
|
/// Unlike `alignBackward`, `alignment` can be any positive number, not just a power of 2.
|
|
pub fn alignBackwardAnyAlign(comptime T: type, addr: T, alignment: T) T {
|
|
if (isValidAlignGeneric(T, alignment))
|
|
return alignBackward(T, addr, alignment);
|
|
assert(alignment != 0);
|
|
return addr - @mod(addr, alignment);
|
|
}
|
|
|
|
/// Round an address down to the previous (or current) aligned address.
|
|
/// The alignment must be a power of 2 and greater than 0.
|
|
pub fn alignBackward(comptime T: type, addr: T, alignment: T) T {
|
|
assert(isValidAlignGeneric(T, alignment));
|
|
// 000010000 // example alignment
|
|
// 000001111 // subtract 1
|
|
// 111110000 // binary not
|
|
return addr & ~(alignment - 1);
|
|
}
|
|
|
|
/// Returns whether `alignment` is a valid alignment, meaning it is
|
|
/// a positive power of 2.
|
|
pub fn isValidAlign(alignment: usize) bool {
|
|
return isValidAlignGeneric(usize, alignment);
|
|
}
|
|
|
|
/// Returns whether `alignment` is a valid alignment, meaning it is
|
|
/// a positive power of 2.
|
|
pub fn isValidAlignGeneric(comptime T: type, alignment: T) bool {
|
|
return alignment > 0 and std.math.isPowerOfTwo(alignment);
|
|
}
|
|
|
|
pub fn isAlignedAnyAlign(i: usize, alignment: usize) bool {
|
|
if (isValidAlign(alignment))
|
|
return isAligned(i, alignment);
|
|
assert(alignment != 0);
|
|
return 0 == @mod(i, alignment);
|
|
}
|
|
|
|
pub fn isAlignedLog2(addr: usize, log2_alignment: u8) bool {
|
|
return @ctz(addr) >= log2_alignment;
|
|
}
|
|
|
|
/// Given an address and an alignment, return true if the address is a multiple of the alignment
|
|
/// The alignment must be a power of 2 and greater than 0.
|
|
pub fn isAligned(addr: usize, alignment: usize) bool {
|
|
return isAlignedGeneric(u64, addr, alignment);
|
|
}
|
|
|
|
pub fn isAlignedGeneric(comptime T: type, addr: T, alignment: T) bool {
|
|
return alignBackward(T, addr, alignment) == addr;
|
|
}
|
|
|
|
test isAligned {
|
|
try testing.expect(isAligned(0, 4));
|
|
try testing.expect(isAligned(1, 1));
|
|
try testing.expect(isAligned(2, 1));
|
|
try testing.expect(isAligned(2, 2));
|
|
try testing.expect(!isAligned(2, 4));
|
|
try testing.expect(isAligned(3, 1));
|
|
try testing.expect(!isAligned(3, 2));
|
|
try testing.expect(!isAligned(3, 4));
|
|
try testing.expect(isAligned(4, 4));
|
|
try testing.expect(isAligned(4, 2));
|
|
try testing.expect(isAligned(4, 1));
|
|
try testing.expect(!isAligned(4, 8));
|
|
try testing.expect(!isAligned(4, 16));
|
|
}
|
|
|
|
test "freeing empty string with null-terminated sentinel" {
|
|
const empty_string = try testing.allocator.dupeZ(u8, "");
|
|
testing.allocator.free(empty_string);
|
|
}
|
|
|
|
/// Returns a slice with the given new alignment,
|
|
/// all other pointer attributes copied from `AttributeSource`.
|
|
fn AlignedSlice(comptime AttributeSource: type, comptime new_alignment: usize) type {
|
|
const info = @typeInfo(AttributeSource).pointer;
|
|
return @Type(.{
|
|
.pointer = .{
|
|
.size = .Slice,
|
|
.is_const = info.is_const,
|
|
.is_volatile = info.is_volatile,
|
|
.is_allowzero = info.is_allowzero,
|
|
.alignment = new_alignment,
|
|
.address_space = info.address_space,
|
|
.child = info.child,
|
|
.sentinel = null,
|
|
},
|
|
});
|
|
}
|
|
|
|
/// Returns the largest slice in the given bytes that conforms to the new alignment,
|
|
/// or `null` if the given bytes contain no conforming address.
|
|
pub fn alignInBytes(bytes: []u8, comptime new_alignment: usize) ?[]align(new_alignment) u8 {
|
|
const begin_address = @intFromPtr(bytes.ptr);
|
|
const end_address = begin_address + bytes.len;
|
|
|
|
const begin_address_aligned = mem.alignForward(usize, begin_address, new_alignment);
|
|
const new_length = std.math.sub(usize, end_address, begin_address_aligned) catch |e| switch (e) {
|
|
error.Overflow => return null,
|
|
};
|
|
const alignment_offset = begin_address_aligned - begin_address;
|
|
return @alignCast(bytes[alignment_offset .. alignment_offset + new_length]);
|
|
}
|
|
|
|
/// Returns the largest sub-slice within the given slice that conforms to the new alignment,
|
|
/// or `null` if the given slice contains no conforming address.
|
|
pub fn alignInSlice(slice: anytype, comptime new_alignment: usize) ?AlignedSlice(@TypeOf(slice), new_alignment) {
|
|
const bytes = sliceAsBytes(slice);
|
|
const aligned_bytes = alignInBytes(bytes, new_alignment) orelse return null;
|
|
|
|
const Element = @TypeOf(slice[0]);
|
|
const slice_length_bytes = aligned_bytes.len - (aligned_bytes.len % @sizeOf(Element));
|
|
const aligned_slice = bytesAsSlice(Element, aligned_bytes[0..slice_length_bytes]);
|
|
return @alignCast(aligned_slice);
|
|
}
|
|
|
|
test "read/write(Var)PackedInt" {
|
|
switch (builtin.cpu.arch) {
|
|
// This test generates too much code to execute on WASI.
|
|
// LLVM backend fails with "too many locals: locals exceed maximum"
|
|
.wasm32, .wasm64 => return error.SkipZigTest,
|
|
else => {},
|
|
}
|
|
|
|
if (builtin.cpu.arch == .powerpc) {
|
|
// https://github.com/ziglang/zig/issues/16951
|
|
return error.SkipZigTest;
|
|
}
|
|
|
|
const foreign_endian: Endian = if (native_endian == .big) .little else .big;
|
|
const expect = std.testing.expect;
|
|
var prng = std.Random.DefaultPrng.init(1234);
|
|
const random = prng.random();
|
|
|
|
@setEvalBranchQuota(10_000);
|
|
inline for ([_]type{ u8, u16, u32, u128 }) |BackingType| {
|
|
for ([_]BackingType{
|
|
@as(BackingType, 0), // all zeros
|
|
-%@as(BackingType, 1), // all ones
|
|
random.int(BackingType), // random
|
|
random.int(BackingType), // random
|
|
random.int(BackingType), // random
|
|
}) |init_value| {
|
|
const uTs = [_]type{ u1, u3, u7, u8, u9, u10, u15, u16, u86 };
|
|
const iTs = [_]type{ i1, i3, i7, i8, i9, i10, i15, i16, i86 };
|
|
inline for (uTs ++ iTs) |PackedType| {
|
|
if (@bitSizeOf(PackedType) > @bitSizeOf(BackingType))
|
|
continue;
|
|
|
|
const iPackedType = std.meta.Int(.signed, @bitSizeOf(PackedType));
|
|
const uPackedType = std.meta.Int(.unsigned, @bitSizeOf(PackedType));
|
|
const Log2T = std.math.Log2Int(BackingType);
|
|
|
|
const offset_at_end = @bitSizeOf(BackingType) - @bitSizeOf(PackedType);
|
|
for ([_]usize{ 0, 1, 7, 8, 9, 10, 15, 16, 86, offset_at_end }) |offset| {
|
|
if (offset > offset_at_end or offset == @bitSizeOf(BackingType))
|
|
continue;
|
|
|
|
for ([_]PackedType{
|
|
~@as(PackedType, 0), // all ones: -1 iN / maxInt uN
|
|
@as(PackedType, 0), // all zeros: 0 iN / 0 uN
|
|
@as(PackedType, @bitCast(@as(iPackedType, math.maxInt(iPackedType)))), // maxInt iN
|
|
@as(PackedType, @bitCast(@as(iPackedType, math.minInt(iPackedType)))), // maxInt iN
|
|
random.int(PackedType), // random
|
|
random.int(PackedType), // random
|
|
}) |write_value| {
|
|
{ // Fixed-size Read/Write (Native-endian)
|
|
|
|
// Initialize Value
|
|
var value: BackingType = init_value;
|
|
|
|
// Read
|
|
const read_value1 = readPackedInt(PackedType, asBytes(&value), offset, native_endian);
|
|
try expect(read_value1 == @as(PackedType, @bitCast(@as(uPackedType, @truncate(value >> @as(Log2T, @intCast(offset)))))));
|
|
|
|
// Write
|
|
writePackedInt(PackedType, asBytes(&value), offset, write_value, native_endian);
|
|
try expect(write_value == @as(PackedType, @bitCast(@as(uPackedType, @truncate(value >> @as(Log2T, @intCast(offset)))))));
|
|
|
|
// Read again
|
|
const read_value2 = readPackedInt(PackedType, asBytes(&value), offset, native_endian);
|
|
try expect(read_value2 == write_value);
|
|
|
|
// Verify bits outside of the target integer are unmodified
|
|
const diff_bits = init_value ^ value;
|
|
if (offset != offset_at_end)
|
|
try expect(diff_bits >> @as(Log2T, @intCast(offset + @bitSizeOf(PackedType))) == 0);
|
|
if (offset != 0)
|
|
try expect(diff_bits << @as(Log2T, @intCast(@bitSizeOf(BackingType) - offset)) == 0);
|
|
}
|
|
|
|
{ // Fixed-size Read/Write (Foreign-endian)
|
|
|
|
// Initialize Value
|
|
var value: BackingType = @byteSwap(init_value);
|
|
|
|
// Read
|
|
const read_value1 = readPackedInt(PackedType, asBytes(&value), offset, foreign_endian);
|
|
try expect(read_value1 == @as(PackedType, @bitCast(@as(uPackedType, @truncate(@byteSwap(value) >> @as(Log2T, @intCast(offset)))))));
|
|
|
|
// Write
|
|
writePackedInt(PackedType, asBytes(&value), offset, write_value, foreign_endian);
|
|
try expect(write_value == @as(PackedType, @bitCast(@as(uPackedType, @truncate(@byteSwap(value) >> @as(Log2T, @intCast(offset)))))));
|
|
|
|
// Read again
|
|
const read_value2 = readPackedInt(PackedType, asBytes(&value), offset, foreign_endian);
|
|
try expect(read_value2 == write_value);
|
|
|
|
// Verify bits outside of the target integer are unmodified
|
|
const diff_bits = init_value ^ @byteSwap(value);
|
|
if (offset != offset_at_end)
|
|
try expect(diff_bits >> @as(Log2T, @intCast(offset + @bitSizeOf(PackedType))) == 0);
|
|
if (offset != 0)
|
|
try expect(diff_bits << @as(Log2T, @intCast(@bitSizeOf(BackingType) - offset)) == 0);
|
|
}
|
|
|
|
const signedness = @typeInfo(PackedType).int.signedness;
|
|
const NextPowerOfTwoInt = std.meta.Int(signedness, try comptime std.math.ceilPowerOfTwo(u16, @bitSizeOf(PackedType)));
|
|
const ui64 = std.meta.Int(signedness, 64);
|
|
inline for ([_]type{ PackedType, NextPowerOfTwoInt, ui64 }) |U| {
|
|
{ // Variable-size Read/Write (Native-endian)
|
|
|
|
if (@bitSizeOf(U) < @bitSizeOf(PackedType))
|
|
continue;
|
|
|
|
// Initialize Value
|
|
var value: BackingType = init_value;
|
|
|
|
// Read
|
|
const read_value1 = readVarPackedInt(U, asBytes(&value), offset, @bitSizeOf(PackedType), native_endian, signedness);
|
|
try expect(read_value1 == @as(PackedType, @bitCast(@as(uPackedType, @truncate(value >> @as(Log2T, @intCast(offset)))))));
|
|
|
|
// Write
|
|
writeVarPackedInt(asBytes(&value), offset, @bitSizeOf(PackedType), @as(U, write_value), native_endian);
|
|
try expect(write_value == @as(PackedType, @bitCast(@as(uPackedType, @truncate(value >> @as(Log2T, @intCast(offset)))))));
|
|
|
|
// Read again
|
|
const read_value2 = readVarPackedInt(U, asBytes(&value), offset, @bitSizeOf(PackedType), native_endian, signedness);
|
|
try expect(read_value2 == write_value);
|
|
|
|
// Verify bits outside of the target integer are unmodified
|
|
const diff_bits = init_value ^ value;
|
|
if (offset != offset_at_end)
|
|
try expect(diff_bits >> @as(Log2T, @intCast(offset + @bitSizeOf(PackedType))) == 0);
|
|
if (offset != 0)
|
|
try expect(diff_bits << @as(Log2T, @intCast(@bitSizeOf(BackingType) - offset)) == 0);
|
|
}
|
|
|
|
{ // Variable-size Read/Write (Foreign-endian)
|
|
|
|
if (@bitSizeOf(U) < @bitSizeOf(PackedType))
|
|
continue;
|
|
|
|
// Initialize Value
|
|
var value: BackingType = @byteSwap(init_value);
|
|
|
|
// Read
|
|
const read_value1 = readVarPackedInt(U, asBytes(&value), offset, @bitSizeOf(PackedType), foreign_endian, signedness);
|
|
try expect(read_value1 == @as(PackedType, @bitCast(@as(uPackedType, @truncate(@byteSwap(value) >> @as(Log2T, @intCast(offset)))))));
|
|
|
|
// Write
|
|
writeVarPackedInt(asBytes(&value), offset, @bitSizeOf(PackedType), @as(U, write_value), foreign_endian);
|
|
try expect(write_value == @as(PackedType, @bitCast(@as(uPackedType, @truncate(@byteSwap(value) >> @as(Log2T, @intCast(offset)))))));
|
|
|
|
// Read again
|
|
const read_value2 = readVarPackedInt(U, asBytes(&value), offset, @bitSizeOf(PackedType), foreign_endian, signedness);
|
|
try expect(read_value2 == write_value);
|
|
|
|
// Verify bits outside of the target integer are unmodified
|
|
const diff_bits = init_value ^ @byteSwap(value);
|
|
if (offset != offset_at_end)
|
|
try expect(diff_bits >> @as(Log2T, @intCast(offset + @bitSizeOf(PackedType))) == 0);
|
|
if (offset != 0)
|
|
try expect(diff_bits << @as(Log2T, @intCast(@bitSizeOf(BackingType) - offset)) == 0);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|